Question

eight years ago the ratio of the age of A to that of B was 5:7 after 16 years the ratio of their ages will be 4:5 what is the difference between the present age of A and B .
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Answer 1

Answer:

Current age of A = A

Current age of B = B = 4x

Current age of C = C = 5x

8 years ago, the ratio of A’s age to B’s age = (A-8)/(B-8) = 4:5

i.e. A's Age < B's Age

B:C = 4:5

i.e. if B = 4x then C = 5x

i.e. B's Age < C's Age

i.e. A < B < C

ALso, Difference of current ages of A and C = C-A = 20

i.e. A = C-20 = 5x-20

Now, using (A-8)/(B-8) = 4:5

i.e. 5A - 40 = 4B - 32

i.e. 5 (5x-20) - 4*(4x) = 40-32 = 8

i.e. 25x - 16x = 8+100 = 108

i.e. 9x = 108

i.e. x = 12

sum of the ages of A, B and C = A+B+C = (5x-20) + 4x + 5x = 14x - 20 = 14*12 - 20 = 148

Answer 2

Answer:

5years ago

5x,7x

10 years hence

(5x+10):(7x+10)=4:5

5(5x+10)=4(7x+10)

Upon simplication

3x=10

X=10/3

50/3+10,70/3+10

120/3+20

40+20=60

Avg=60/2=30