Lily, Lucas, Jonathan and Olivia share the same hobby of collecting erasers. The average number of erasers collected by the 4 friends is 29. Lucas collected 6 more erasers than Jonathan but 17 fewer erasers than Lily. Olivia collected 5 erasers fewer than Jonathan. Find the average number of erasers collected by Lucas, Jonathan and Olivia. Round off your answer to the nearest whole number.
Number of erasers Jonathan collected = 1 u
Number of erasers Lucas collected = 1 u + 6
Number of erasers Lily collected = 1 u + 6 + 17 = 1 u + 23
Number of erasers Olivia collected = 1 u - 5

Total number of erasers collected
= 4 x 29
= 116

Total number of erasers collected in units
= 1 u + 1 u + 6 + 1 u + 23 + 1 u - 5
= 4 u + 24

4 u + 24 = 116
4 u = 116 - 24 = 92

1 u = 92 ÷ 4 = 23

Total number of erasers collected by Lucas, Jonathan and Olivia
= 1 u + 6 + 1 u + 1 u - 5
= 3 u + 1
= 3 x 23 + 1
= 70

Average number of erasers collected by Lucas, Jonathan and Olivia
= 70 ÷ 3
≈ 23 (Round off to the nearest whole number.)

Answer(s): 23