The present ages of A and B are in the ratio 3 : 4. Ten years ago, this ratio was 4 : 7. The present ages of A and B are respectively?

Let's solve this step by step:

Step 1: Let's assume the present ages of A and B are 3x and 4x respectively.

Step 2: According to the problem, ten years ago, the ratio of their ages was 4 : 7. So, we can write it as (3x - 10) / (4x - 10) = 4/7.

Step 3: Cross multiply to solve for x. We get 7*(3x - 10) = 4*(4x - 10).

Step 4: Simplify the equation to get 21x - 70 = 16x - 40.

Step 5: Rearrange the equation to find the value of x. We get 21x - 16x = 70 + 40, which simplifies to 5x = 110.

Step 6: Solve for x. We get x = 110 / 5 = 22.

Step 7: Substitute x = 22 in 3x and 4x to get the present ages of A and B. So, A's age is 322 = 66 years and B's age is 422 = 88 years.

So, the present ages of A and B are 66 years and 88 years respectively.