Answer: The twins are 11 years each and their older sister is 18 years.
Explanation:
Let represent the age of one of the boys as x and that of the older sister as y.
The boys were born 7 years after their older sister can be represented as
Y = x + 7
This year, the product of the three siblings' ages is exactly 2138 more than the sum of their ages.
This can be represented as; x × x × y= 2138 + x + x + y
X^2 × y = 2138 + 2x + y….......(eqn 1)
Recall that Y = x + 7
Subs Y into eqn 1
X^2( x+7) = 2138 + 2x + x+7
X^3 +7x^2 - 3x - 2145 = 0
Solving this polynomial
X= 11 and y = 18.
The ages of the twins are 11 years each