The product of two positive numbers is 616. If the ratio of the difference of their cubes to the cube of their difference is 157:3, then the sum of the two numbers is
Correct Answer :
50
Solution :
The correct option is 2 (which corresponds to 50).
Let the two positive numbers be and , with .
We are given that their product is:
We are also given the ratio of the difference of their cubes to the cube of their difference is 157:3:
Recall the algebraic identities:
and
Substituting these into the ratio equation, we can cancel since the numbers are positive and distinct (as their ratio involves a non-zero difference):
We can rewrite the numerator as :
Dividing the terms on the left side, we get:
Subtract 1 from both sides:
Substitute into the equation:
Simplify the equation by dividing both sides by 154 (note that ):
Cross-multiplying gives:
Since , we have:
We need to find the sum of the two numbers, . We can use the relation:
Substitute the values of and :
Taking the positive square root (since and are positive):
Thus, the sum of the two numbers is 50.
Access expert-curated educational resources and study materials—completely free.
Create, conduct, and manage professional online assessments with Mindyard. Perfect for teachers and institutes.
Copyright © 2026 Mindyard. All Rights Reserved.