Word problems, commission and royalty 6th vrade

Question

Ali, Ben and cliff plant seedlings in their neighborhood park. Ali plants 40% of the total number of seedlings, Ben plants 45% of the total number of seedlings, and cliff plants the rest of the seedlings. If cliff plants 87 seedlings, how many seedlings do the three boys plant together?

Please answer in 6th grade level thank you so much for your help.

Answer 1

A plants 40% of seedlings, B plants 45% and C plants 100% - (40+45) = 15%

C planted 87 seedlings which are 15% or a proportion of 0.15 of all seedlings.

Divide 87 by 0.15 to get n=580 seedlings planted by the 3 boys together.