Answer:
His cousin is 15.
Subtract and then divide.
Explanation:
So, Santosh (49) is 4 years older than the triple of the age of his cousin (c)... we then get this equation system:
49 = 4 + 3c
We just have to resolve this simple system to find the age of the cousin.
We first subtract 4 on each side:
45 = 3c
Then we divide each side by 3:
15 = c
His cousin is 15 years old.