2017 SSC CGL 19 Aug Shift-3

Question 87

If $$a^{3} + b^{3}$$ = 152 and a + b = 8, then what is the value of ab?

Solution

$$a^{3}+b^{3}=(a+b)^{3}-3ab(a+b)$$

$$152=(8)^{3}-3ab(8)$$

$$152=512-24ab$$

$$24ab=360$$

$$ab=15$$

So the answer is option D.

Share on Whatsapp Share on Whatsapp

Create a FREE account and get:

  • Free SSC Study Material - 18000 Questions
  • 230+ SSC previous papers with solutions PDF
  • 100+ SSC Online Tests for Free

cracku

Boost your Prep!

Download App