Soniya got married 15 years ago. Her present age is 8/5 times her age at the time of her marriage. Her sister was 8 years younger to her at the time of her marriage. Find the present age of her sister.

The correct answer is 32 years.

Let us solve this step-by-step to find the present age of Soniya's sister.

Step 1: Define variables for Soniya's age.
Let Soniya's present age be $x$ years.
Since Soniya got married 15 years ago, her age at the time of her marriage was $x-15$ years.

Step 2: Formulate the equation according to the problem statement.
We are given that her present age is $\frac{8}{5}$ times her age at the time of her marriage.

$x=\frac{8}{5}\times (x-15)$

Step 3: Solve for $x$ (Soniya's present age).
Multiply both sides by 5:

$5x=8(x-15)$

Expand the right side:

$5x=8x-120$

Rearrange terms to isolate $x$:

$8x-5x=120$

$3x=120$

$x=\frac{120}{3}=40$

So, Soniya's present age is 40 years.

Step 4: Find the present age of Soniya's sister.
The age difference between two siblings remains constant throughout their lives. Since her sister was 8 years younger at the time of Soniya's marriage, she will always be 8 years younger than Soniya.

Present age of Soniya's sister = Soniya's present age - 8 years

$\text{Present age of sister}=40-8=32\text{years}$

Thus, the present age of Soniya's sister is 32 years.