Posted by chrissy on Thursday, August 2, 2007 at 8:36pm.
If 3/4 of a class is absent and 2/3 of those present leave the room, what fraction of the original class remains in the room?
my book says..
if 3/4 are absent, 1/4 are present
hows that so?
then it says if 2/3 of the 1/4 present , 1/3 of the 1/4 remain leave 1/3x1/4 =1/12 I dont understand? Do I add or?? Im not sure please help me
I think you'll find it easier if you introduce a variable for the number of students in the room. Suppose there are N students.
If a fraction of 3/4 is absent, then that means that the number of absent students is 3/4 N. Now the total number of students is N, so the difference
N - 3/4 N is the number of students that are present.
N - 3/4 N = (1-3/4) N = 1/4 N
So, a fraction 1/4 of the number of students are present.
ok so its 1-3/4? can you subtract that for me im not sure how to
Imagine a pizza that's cut into four equal parts. If your friends eat three pieces, they've eaten 3/4 of the pizza. That leaves 1/4 of the pizza for you.
Showing it mathematically:
1 - 3/4 =
4/4 - 3/4 = 1/4
Another way of looking at 1 - 3/4 is to think of money.
A dollar has 4 quarters (4/4). If you spend 3 quarters (3/4), you have one quarter (1/4) left.
The second part of your question states 1/3 of the 1/4 remain leave
. Remember that the word "of" indicates you need to multiply. So ...
1/3 x 1/4 = ??
If you have trouble remembering how to multiply fractions, check one of these sites:
Or does it state that 2/3 of
the 1/4 present leave? If so, then the multiplication problem is 2/3 x 1/4 = ??
I wish they would of left me 2/4 of the pizza. Thank You very Much! that explains it!
Answer this Question
Math - In a class of 550 students, students may take all, none, or a combination...
Statistics - A mathematics class has 200 members. If there is 12% absentee rate ...
Maths - A mathematics class has 200 members. If there is 12% absentee rate per ...
GEOMETRY - Decide which of the variables described is likely to have a normal or...
Elementary Math - Decide which of the variables described is likely to have a ...
Mathematics - Among 500 freshmen pursuing a business degree at a university, 313...
survey of mathematics - in a survey of 24 college student,it was found that 16 ...
statistics - The average marks of 30 students in mathematics is 69. If the class...
Maths - what are the meanings of Mathematics of Buying and Mathematics of ...
probability - out of 250 students interviewed at a community college, 90 were ...