question 1

If 6x - 3y = 30 and 4x = 2 - y then find x + y.

...

question 3

Which of the following sets is not closed under addition?

A Whole Numbers

B Integers

C Even Integers

D Odd Integers

...

question 20

The area of a square is 100. The length of its diagonal is approximately:

A 12

B 13

C 14

D 15

The issue is not doubting whether such tests measure something - they provide a measure of what you know/reasoning skills based on that knowledge at whatever age you take them. People who do better on them are, in some sense, "smarter," on average than those who do worse on them. But they don't measure innate intelligence. They don't measure the limits of individual potential. They don't provide a comprehensive measurement of all dimensions of what we might think of as "smartness." They're quite likely culturally biased in some ways. And, most importantly, to a great degree they simply measure your level of education.