Question

After Khalil gave Benjamin 3/5 of the rocks in his collection, Benjamin had 70 rocks. If Benjamin had 25 rocks in the beginning, how many rocks did Khalil have in the beginning?

Answer 1

Benjamin had 25 rocks in the beginning...70 - 25 = 45
so 3/5 of Khalil's rocks are 45 rocks...

(3/5)/45 = 1/x
cross multiply
3/5x = 45
x = 45 * 5/3
x = 225/3
x = 75 <== khalil had 75 rocks to begin with