Posts by Marth
Total # Posts: 765

SS
So... what were the correct answers? 
math
It depends on the distribution of x bar. 
math
6 topping choices, 2 toppings per pizza: 6 choose 2, which is 6!/(2!4!) 
Stats/Probability
"Red OR Yellow" should be a giveaway. Here P(A and B)=0 because a red car is not yellow. P(A)+P(B)=0.12+0.04 = 0.16 
computer science
4×512MB = 2GB = 2^31 bytes. To address any byte requires 31 bits. 
theoretical probability
There are 2 digits (8,9) greater than 7. So every student has a 1/5 chance of choosing a digit greater than 7. With 25 students, the expected number that choose a digit greater than 7 is 25/5 = 5. I would not say the "predicted" number, but rather the "expected&... 
math
b) He can throw 5 types of pitches each pitch. With 5 pitches, there are 5^5 possible combinations. 
algebra
When the world record is less than 3.1, R is less than 3.1. 3.1 = 0.075t + 3.85 Solve for t (in years after 1930). 
computer science
File sizes are given in bytes, while download speeds are given in bits. 4 GB = 4*1024 MB = 4*1024^2 KB = 4*1024^3 Bytes  4*1024^3*8 bits. 43.2kbps = 43.2*1000 bits per second. The time required is 795.364s, or 220.935 hours. Note that 43.2kbps is quite a low bandwidth. 
Math
The fence forms the perimeter of the rectangle. What is the perimeter? 
geometry
It doesn't. 100 is not divisible by 6, nor is 83 divisible by 5. 
Math
13 is a good guess. But when in 2011 do they actually turn 13? 
math
What is the equation for the volume of a sphere? Try googling it. 
math
How many inches are in a foot? 
Trig Check my answer Please
What is the length of <1,2>? Divide <1,2> by its length, giving the result a length of 1  an unit vector. 
math
How could you get only x on the left hand side? 
math
Is the domain of g equal to A? Is the range of g a subset of B? if both are true, then g maps A to B. 
math geometry
Use Pythagorean Theorem. a^2 + b^2 = c^2, where c is the hypotenuse of the right triangle. 
Math
Find the slope and y intercept of each, and compare. m = (y1y2)/(x1x2) to find the slope. y  y1 = m(xx1) to write the line in slopeintercept form. 
Algebra
You can factor out a 4a from each term. 
Math Algebra 2
Substitute in the values of p and r. p = 10 r = 4 p^2  r^2 = (10)^2  (4)^2 = ? 
MATH
No two numbers add to 50. Therefore we must use at least 3 numbers to get the sum. 25+19+6 = 50: a solution exists for 3 numbers. 
math
(1/8)(1/8)2+(1/8)3 = (1/8)(12+3) by factoring. 
beginning algebra
2 + 7/y = 3/5 7/y = 3/5  2 y/7 = 1/(3/5  2) 
College Algebra
Correct 
algebra
The probability that Jonas gets an orange is 5/11. Given that Jonas gets an orange, the probability that Beth gets an apple is 4/10. So the probability that Jonas gets an orange and Beth gets an apple is (5/11)*(4/10). 
algebra
y  y1 = m(x  x1) The point (x1, y1) is given as (4, 5). The slope m is given as 3. 
MATH
881/5 = 880/5 + 1/5 
Geometry
Let x and y be the sides. By Pythagorean Theorem, x^2 + y^2 = 600^2. x+y+600 = 1400 
Math
Elaine takes 2.8s more than Pamela: Elaine takes 2.8s + 52.3s = 
Math
To find the inverse, swap f(x) and x: f(x) = 10x5 x = 10f^1(x)5 Now solve for f^1(x). 
Math
Set up a proportion: 8%/56 = 100%/x 
Algebra
x^26x3=0 x = (b +/ sqrt(b^24ac))/(2a) x = (6 +/ sqrt(6^2  4(1)(3)) ) / (2(1)) 
algebra
Plug the values in. h = 50m t = 2s v = 30m/s h+vt+4.9*t^2=? 
math
The difference of two squares is a^2b^2, for a and b any expression. It should be easy to determine if a polynomial fits that form. 
physics
V=d/t d=V*t Let t be the time the man is jogging. t2 is the time the dog is running (since the dog waits 2s). When they catch up with each other displacement will be equal. (4m/s)(t2)=(1.8m/s)(t) 
Preap Physics!!
There are several types of potential energy  spring potential energy, chemical potential energy, etc. 
math
If the relationship is linear, then the line formed by any two points will pass through all points. Find the line through the first two points. Then check to see if the rest of the points are on that line. 
algebra
There are two solutions because of the absolute value sign. x3x+5 = 7 or x3x+5 = 7 
algebra 2
yes 
algebra 2
You can factor out 4x from both terms. 
algebra
Jeffs car takes 20% less gas, so it gets 21/(10.2) miles per gallon. To drive 570 miles at 21 miles per gallon requires 570/21 gallons. 
math
Teaching makes you learn something well. You've had scientific notation in class, right? Pretend I don't know scientific notation, and explain to me what it is. (That will be your answer). 
Algebra
Let x be the amount of time of the breakeven point. Then 84+50x = 60x. 
Algebra 2
Use synthetic division with 3, then factor the remainder. 
algebra
f(x) = 2x^23x f(0) = 2(0)^23(0) = 0 f(1) = 2(1)^23(1) f(2)=? 
math
Let a be the value of "a", e be the value of "e", etc. for i, o, and u. Audacious has a u a i o u = 260. So 2a+i+o+2u = 260. Do the same for the other 4 words; you have 5 equations for 5 variables. 
algebra 2
The zeroes are 1, 2, and 3, so the factors are (x1), (x2), and (x3). Those are 3 factors for a 3rd degree polynomial, so no other factors are needed. f(x) = C*(x1)(x2)(x3), where C is any constant. f(0) = 18 allows you to determine C. 
probability
There are 15 choose 4 ways to choose 4 toppings. There are 15 choose 2 ways to choose salami, green pepper, and 2 other toppings. P{salami and green pepper) = C(15, 2) / C(15,4). 
Math: Algebra 2
Try factoring out (2x3) through grouping. 
Math
Suppose you buy x shirts to be shipped as one order. What is the cost of the shirts? What is the cost of shipping? 
geometry
The diagonal forms a right triangle with 2 sides of the square. The sides are of equal length, so you can use Pythagorean Theorem to find a side of the square. 
Algebra
What variables did you use in part a? 
Algebra II
x^2+2x3 factors into (x+3)(x1). You can divide x^45x^316x^2+23x3 by (x+3) and (x1) using synthetic division, which may be easier. 
math analysis
If csc(x) = 30/150, sin(x) = 150/30. That is not in the range of sine. 
Math
Try writing an equation for each problem. It's easy to make a mistake while glancing over the answer choices. 
Calculus
The derivative of ln(u) is u'/u. Use Chain Rule for the rest. 
math
The points at the tail of the skew affect the mean, but the median will remain in the middle of the curve. 
algebra
2x<2x1 < is not defined. 
Math
Use L'hopital's Rule. 
math
a > b = "a is greater than b" a < b = "a is less than b" 
algebra
What is your question? 
physics
q1 exerts a force on q in the positive direction, and q2 exerts a force on q in the negative direction. F = k(q1q2)/r^2 is the force exerted on one point charge by another. ΣF = k(q*q1)/(0.24)^2  k(q*q2)/(0.37)^2 = 24. q and q1 are given. q2=? 
Math
The player makes 60% of the shots. So the odds are 60:40 in favor of her making the first shot. 
PhysicsPlease check
1) Yes, the gravitational force diminishes the farther you get, but by what factor? Check the equation. 2) The speed of the earth keeps it in orbit around the sun. Changing the mass changes the gravitational force, which is also the centripetal force for the orbit. 
Math
Yes 
algebra
What is your question? 
math
You gain $3 if you get a 6, and always pay $0.90. E[X] = (1/6)*3  $0.90 
math
Pythagorean Theorem: a^2 + b^2 = c^2 c is the hypotenuse 
algebra
25% was marked off the original price of $88. 
fraction x whole number
7/10*30 = 7/10*10*3 = 7*3 = 21 
algebra
If 3n+5 = 7, then 3n+5 = 7 or 3n+5 = 7. There are two possibilities for n; find both. 
Math
18 < 20w 1820 < 20w20 2 < w Flip the inequality sign when multiplying by 1. 2 > w 
science
The boiling point and condensation point are identical. 
Math
Yes 
Math prealgebra
3/1.65 = 5/x 
math
Let x be the amount of money Beth has. Let y be the amount of money Suzy has. "beth has $0.60 more than suzy." x = 0.60+y. "together they have $8.20." x+y = 8.20 Solve the system of equations. 
Math
< 10 ... 7 6 ... 0 1 2 ... > Numbers are ascending left to right. Is 7 to the left or to the right of 6? 
Math
Draw a number line, and label 7 and 6. 
Math
x+8 < 11 x+88 < 118 x < 3 Inequalities are almost like regular equations. 
Math
x+8<11 implies x<3. What is your question? 
PreAlgebra
12+5 > y5+5 17 > y 
math
Ok. Then the perimeter of the triangle is w + l/2 + 5. So w+l/2+5 = 12m, and 2(l+w)=22m. 
math
Is the base of the triangle the width of the rectangle, and the height of the triangle half the length of the rectangle? 
math
Are you referring to the triangle formed by the diagonal of the rectangle and two of its sides? If the dimensions are 8m by 3m, the hypotenuse of said triangle cannot be 5m. 
math
The perimeter of the rectangle is 22m. So 2(l+w) = 22. l+w = 11 l = 11w Also, l^2+w^2 = 5^2 by Pythagorean Theorem. Substitute in l = 11w: (11w)^2+w^2=5^2 
math
Let l be the length, and w be the width, of the rectangle. The perimeter of the rectangle is 2(l+w). The perimeter of the triangle is l+w+sqrt(l^2+w^2). sqrt(l^2+w^2) is the hypotenuse of the triangle. There are two equations and two variables. Find l and w. 
math
(2/5)Q <= 18 Q <= (18)/(2/5) 
Math
2+m < 2 2+m2 < 22 m < 0 
Math
I appreciate trying to help, but please work out the problems to show how the answer is reached. (It also helps to check your work). Standard form of a line is ax+by = c, with a, b, and c integers. y+2 = (1/2)(x4) Distribute the (1/2). y+2 = x/22 Multiply by 2 to make the ... 
Math
Factoring the tens is a technique for mental multiplication which relies on the fact that 10*n, for any real number n, is easy to compute. 6*2 = 12 is a memory value. 6*20 = 6*2*10 = 12*10 = 120 60*20 = 6*10*2*10 = 12*10*10 = 1200 
algebra
Substitute in x = 355y in 4x+9y = 52. 4(355y)+9y = 52 Solve for y. Then, plug the value of y into either of the original equations to find x. 
algebra
6.67*10^11 = 6.67/10^11 
Math
104(5x+1) Distribute the 4 =1020x4 =620x 
Math
This is a simple triangle problem  it may help to draw it out. Draw the height perpendicular to the ground, and the ramp is the hypotenuse. The solution is a proportion. Let x be Pam's height. Then 15/9 = (15+20)/x. x=? 
Math/Trig
The period of the parent function is 2pi. The factor of 1/2 applied to x changes the period to 2pi/(1/2) = 4pi. 
Math
t is the price of the movie ticket. We know that 3 tickets is less than twenty dollars, because the student got change back. 3t < 20 
math
That is an expression. What is your question? 
math
8*5*9 = 4*2*5*9 = 4*10*9 = 36*10 = 360 
algebra
Given the slope m and the point (x1, y1), use the equation yy1 = m(xx1) to find the equation of the line.