jasper got a 100% on his first test, an 85% on his second test, and he didn't want to talk about his score on the third test. If jasper's overall average on all three tests was 64%, what is his score on the 3rd test?
Let x be the score on the third test.
His overall score on the three tests is (100 + 85 + x)/3 = 64.
Adding the scores on the three tests, we get 100 + 85 + x = 64 * 3.
Combining like terms, we get 185 + x = 192.
Subtracting 185 from both sides, we get x = 7.
Therefore, Jasper's score on the third test is 7. Answer: \boxed{7}.