PrepRung
Sign inSign up free

CAT 2017 Slot 1 · Quant · Averages · easy

The average of 11 numbers is 36. The average of the first six numbers is 32 and the average of the last six numbers is 41. What is the sixth number?

Single correct option

The average of 11 numbers is 36. The average of the first six numbers is 32 and the average of the last six numbers is 41. What is the sixth number?
  1. A. 38
  2. B. 40
  3. C. 46
  4. D. 42
Show answer and solution

Answer: (D) 42

The sixth number is counted in both the 'first six' and the 'last six'.

Sum of first six = 6 × 32 = 192.
Sum of last six = 6 × 41 = 246.
Sum of all 11 = 11 × 36 = 396.

Adding the two groups counts the 6th number twice: 192 + 246 = 396 + (6th number).

6th number = 438 − 396 = 42.
Report a mistake

Original question written in the CAT 2017 Slot 1 pattern and checked twice for the correct answer. Not an official question paper. How we write and check questions · Corrections policy · Report a mistake