Question 53464
Mike picked three-fourths of the pears on his father's tree. After Mike finished, Sylvia picked two-thirds of the pears that were left on the tree. After Sylvia finished, there were twenty pears left on the tree. How many pears were on the tree before Mike and Sylvia started picking? 
:
Let x = number of pears originally on the tree
:
"Mike picked three-fourths of the pears "
 Mike picked: (3/4)x, then (1/4)x is left
:
"Sylvia picked two-thirds of the pears that were left"
If Sylvia picked(2/3) then 1/3 are left
:
(1/3)(1/4)x = 20
 (1/12)x = 20
       x = 20 * 12
       x = 240 pears originally on the tree
:
Check: 240 - 3/4(240) = 60
        60 - 2/3(60)  = 20