The combined mean of the numbers 9, 12, 15, 18, 20, 22 increases by 2 if the number ___ is taken instead of 15.

Q.The combined mean of the numbers 9, 12, 15, 18, 20, 22 increases by 2 if the number ___ is taken instead of 15. (a) 27 (b) 19 (c) 21 (d) 25

Answer: A

(9+12+15+18+20+22)−15+x = 9+12+15+18+20+22+(6×2)
Or, x = 15 + 12 = 27