A pencil cost 2/3 as much as an eraser. Tom bought a number of pencils and erasers. The total cost of all the pencils was 4 times as much as the total cost of all the erasers. Tom bought 35 pencils and erasers. How many pencils did Tom buy altogether?
+36916 p = 2/3 e costs given
(p x) = 4 e ( 35-x)
2/3 e x = 140 e - 4ex
4 2/3 ex = 140 e
4 2/3x = 140
x = 140 / (4 2/3) = 30 = number of pencils
check: 30 p = 5 e * 4
30 * 2/3 e = 20 e
20 e = 20 e Yes .....
