Question 1002622
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In a class of 16 students, 13 students took a Math test, 10 students took Science test, and 9 students took both tests. 
How many students did not take any of the tests?
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How many students took the Math test only and didn't took the Science test?
Their number is 13 - 9 = 4.


How many students took the Science test only and didn't took the Math test?
Their number is 10 - 9 = 1.


How many students took at least one, the Math or the Science test?
Their number is 9 + 4 + 1 = 14.


Hence, 16-14 = 2 students didn't take any of the tests.


<U>Answer</U>. 2.