SOLUTION: The ages of A and B are in the ratio 5:7.Four years from now the ratio of their ages will be 3:4 .Find their present ages.

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Question 762858: The ages of A and B are in the ratio 5:7.Four years from now the ratio of their ages will be 3:4 .Find their present ages.
Answer by ramkikk66(644) About Me  (Show Source):
You can put this solution on YOUR website!
If A's age is 5*x, B's age is 7*x.
4 years later, A will be 5*x + 4 years old
4 years later, B will be 7*x + 4 years old
It is given that %285%2Ax+%2B+4%29%2F%287%2Ax+%2B+4%29+=+3%2F4
Cross-multiplying
20%2Ax+%2B+16+=+21%2Ax+%2B+12
x+=+4
So A's age is 20 and B's age is 28.
Check: In 4 years, A will be 24 and B 32. Ratio will be 3:4.
:)