Hi Vincen,

We're told that Peter went to the store to buy paint. Small cans cost $30 and larger cans cost $80. We're asked for the number of small cans of paint he bought.

1) Peter spent $220 on paint.

Since $220 is a relatively small total, we can 'brute force' the possible solutions by TESTing VALUES.
Could there be....
0 large cans... $220 is NOT divisible by $30, so 0 large cans is NOT possible.
1 large can... $140 is NOT divisible by $30, so 1 large can is NOT possible.
2 large cans... $60 IS divisible by $30 - and the answer to the question would be 2.
3 large cans would cost $240 - which is higher than the $220 total, so 3 large cans is NOT possible.

Thus, there is only 1 answer (2 small cans).
Fact 1 is SUFFICIENT

2) Peter bought four cans of paint in total.

With the information in Fact 2, Peter could have bought from 0 - 4 small cans (inclusive) of paint.
Fact 2 is INSUFFICIENT

Final Answer: A

GMAT assassins aren't born, they're made,
Rich