John, Lucy, Jacob and Lily share the same hobby of collecting pens. The average number of pens collected by the 4 friends is 22. Lucy collected 9 more pens than Jacob but 18 fewer pens than John. Lily collected 4 pens fewer than Jacob. Find the average number of pens collected by Lucy, Jacob and Lily. Round off your answer to the nearest whole number.
Number of pens Jacob collected = 1 u
Number of pens Lucy collected = 1 u + 9
Number of pens John collected = 1 u + 9 + 18 = 1 u + 27
Number of pens Lily collected = 1 u - 4

Total number of pens collected
= 4 x 22
= 88

Total number of pens collected in units
= 1 u + 1 u + 9 + 1 u + 27 + 1 u - 4
= 4 u + 32

4 u + 32 = 88
4 u = 88 - 32 = 56

1 u = 56 ÷ 4 = 14

Total number of pens collected by Lucy, Jacob and Lily
= 1 u + 9 + 1 u + 1 u - 4
= 3 u + 5
= 3 x 14 + 5
= 47

Average number of pens collected by Lucy, Jacob and Lily
= 47 ÷ 3
≈ 16 (Round off to the nearest whole number.)

Answer(s): 16