SSC CGL – Combined Graduate Level Examination · Question 53
Evaluate: 1/(√16 − √15) − 1/(√15 − √14) + 1/(√14 − √13) − 1/(√13 − √12) + 1/(√12 − √11)
Show answer & explanation
Answer: (A) 4 + √11
Explanation
Each 1/(√a − √b) = √a + √b; the terms telescope to √16 + √11 = 4 + √11.