Raeann, Benjamin, Joshua and Roshel share the same hobby of collecting coins. The average number of coins collected by the 4 friends is 25. Benjamin collected 8 more coins than Joshua but 13 fewer coins than Raeann. Roshel collected 5 coins fewer than Joshua. Find the average number of coins collected by Benjamin and Roshel. Round off your answer to the nearest whole number.
Number of coins Joshua collected = 1 u
Number of coins Benjamin collected = 1 u + 8
Number of coins Raeann collected = 1 u + 8 + 13 = 1 u + 21
Number of coins Roshel collected = 1 u - 5

Total number of coins collected
= 4 x 25
= 100

Total number of coins collected in units
= 1 u + 1 u + 8 + 1 u + 21 + 1 u - 5
= 4 u + 24

4 u + 24 = 100
4 u = 100 - 24 = 76

1 u = 76 ÷ 4 = 19

Total number of coins collected by Benjamin and Roshel
= 1 u + 8 + 1 u - 5
= 2 u + 3
= 2 x 19 + 3
= 41

Average number of coins collected by Benjamin and Roshel
= 41 ÷ 2
≈ 21 (Round off to the nearest whole number.)

Answer(s): 21