Question

Eric and his work crew have 50 trees to plant. In 8 hours today they planted 40 trees. If they work at the same rate tomorrow how long will it take to finish planting the trees

Answer 1

8 hrs - 40 trees
x hrs - 50 trees.
8:x = 40:50
x = 10 hrs.
It will take two hrs to finish planting the trees.

Answer 2

calculate the rate: 8 hrs -> 40 trees
so 1 hour -> 5 trees (40/8 = 5)
in the next day, Eric has 10 trees to plant
so he will need 2 more hours
make the total hours = 10 hours