Answer: 60
Explanation:
From the question, we are informed that pencils come in packages of 10 while erasers come in package of 12 .
We are further told that Phillip wants to purchase the smallest number of pencils and erasers so that he will have exactly 1 eraser per pencil, this simply means that we have to calculate the lowest common multiple for 10 and 12.
Multiples of 10 = 10, 20, 30, 40, 50, 60,
Multiples of 12 = 12, 24, 36, 48, 60, 72
Therefore, the packages of pencils and erasers that Phillip should buy will be 60