NECO 2022 · Paper 1 · Q50

The mean age of seven children is 10 years. The ages (in years) of six of the children are 3, 6, 8, 14, 15 and 16. Find the modal age.

Worked solution (try it first)

The seventh child is $7 \times 10 - 62 = 8$ years old, so the ages are 3, 6, 8, 8, 14, 15, 16.
The mode is the most common age: 8 appears twice, so the modal age is 8 years, option B.