math i need help 3 questions
posted by Bladimir on .
1. The numerator and denominator of a fraction are in the ratio of 3 to 4. If 4 is added to the numerator and subtracted from the denominator, the value of the resulting fraction is 4/3. The numerator of the original fraction is
A. 12
B.
C. 3
D. 4
2. If it takes b hours to walk a certain distance at the rate of 3 miles an hour, the number of hours it takes to return the same distance at 4 miles an hour is
A. 4/3
B. 4b/3
C. 3b/4
D. 3/4
3. The perimeter of a rectangle is 20 inches and its length is 6 inches. The area of the rectangle in square is
A. 20
B. 24
C. 60
D. 48

number 1 choice b is 9

I'll do #1. How about you show some effort on the others? Just write the words in symbols.
If the fraction is n/d, then we are told
n/d = 3/4
(n+4)/(d4) = 4/3
Work through all that, and you have n=12,d=16
check:
12+4 / 164 = 16/12 = 4/3
OK