A batsman had a certain average of runs for 16 innings. In the 17th innings, he made a score of 87 runs thereby increasing his average by 3. What is his average after 17 innings?  Choose the correct choice
A) 39  B) 88  C) 266  D) 278  E) 221

Rationale: explanation : assume his initial average = xx his total runs after 16 innings = 16 xx after scoring 87 runs his average got increased by 3 to xx + 3 so his total runs after 17 innings = 17 × ( xx + 3 ) but it was given that the difference in the total scores after 16 innings and 17 innings = 87 therefore 17 × ( x + 3 ) − 16 x = 87 ⇒ x = 3617 × ( x + 3 ) − 16 x = 87 ⇒ x = 36 his new average = 36 + 3 = 39 answer : a
Answer: A