Whole Number P6

A total of 548 adults and teenagers collected newspapers for a recycling project. Each adult collected 12 kg of newspaper. The teenagers worked in groups of 4 and each group collected 9 kg of newspapers. At the end of the project, a total 5250 kg of newspaper were collected. How many teenagers took part in the recycling project?


4 adults --> 12 x 4 = 48 kg

4 teenagers --> 9 kg

548 teenagers --> 548/4 x 9 = 1233 kg

5250 - 1233 = 4017 kg

48 - 9 = 39 kg

4017 / 39 = 103 groups of adults

103 x 4 = 412 adults

548 - 412 = 136 teenagers

136 teenagers took part.

Check
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136/4 x 9 + 412 x 12 = 5250 kg  (correct)


4 teenagers --> 9 kg

4 adults --> 4 x 12 = 48 kg

548 adults --> 548 x 12 = 6576 kg

6576 - 5250 = 1326 kg

48 - 9 = 39 kg

1326 / 39 = 34 groups of teenagers

34 x 4 = 136 teenagers

136 teenagers took part.