IBPS RRB Office Assistant 2018 Paper

Given, A2−B2=252 ... (i)
and A + B = 42 ...(ii)
From Eq. (i)
⇒ (A+B)(A−B)=252
[∵A2−B2=(A+B)(A−B)]
⇒ 42 x (A - B) = 252
[∵ put the value of A + B]
⇒ A−B=

252

42

A - B = 6 ...(iii)
Subtracting Eq. (iii) from Eq. (ii),
2B = 36 ⇒ B = 18