Question

To receive a driver license, sixteen year-olds at Culliver High School have to pass both a written and a practical driving test. Everyone has to take the tests, and no one failed both tests. If 30% of the 16 year-olds who passed the written test did not pass the practical, how many sixteen year-olds at Culliver High School received their driver license? (1) There are 188 sixteen year-olds at Culliver High School. (2) 20% of the sixteen year-olds who passed the practical test failed the written test.

Answer 1

Both statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.

Explanation:

Consider the provided information.

Sixteen year-olds at Culliver High School have to pass both a written and a practical driving test.

Everyone has to take the tests, and no one failed both tests.

30% of the 16 year-olds who passed the written test did not pass the practical,

Statement 1: There are 188 sixteen year-olds at Culliver High School.

That means 30% of 188 passed in written test.

Or 70% of 188 sixteen year old passed in one or both test.

But we need to find the number of sixteen year-olds at Culliver High School received their driver license?

Which is not possible,

Thus, the statement is insufficient.

Statement 2: 20% of the sixteen year-olds who passed the practical test failed the written test.

That means 20% passed in practical test only and we know that 30% of sixteen year-olds passed in written test.

Therefore, 50% of total passed in both.

But this tells us the percentage of student passed in both and we wants a definite number,

Thus, the statement is not sufficient alone.

Therefore, Both statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.