BTGmoderatorDC wrote:Is the average (arithmetic mean) of 5 different positive integers at least 30?
(1) Each of the integers is a multiple of 10
(2) The sum of the 5 integers is 160
OA D
Source: GMAT Prep
Average = (SUM of terms)/(# of terms)
Since we're told what the average is, the real question becomes, "What is the sum of the terms?" That's the information we need to know in order to answer the question.
Statement (1) First, a quick point - zero is an integer, and zero is also a multiple of 10 (10*0 = 0), but since zero is not a POSITIVE integer (it's neither negative nor positive), it can't one of the 5 numbers.
The smallest possible numbers, therefore, are 10, 20, 30, 40, 50. We can (easily) find the sum, so statement (1) gives us sufficient info to answer the question. \(\Large{\color{green}\checkmark}\)
Statement (2) clearly tells us exactly what we need to know, as well. \(\Large{\color{green}\checkmark}\)
Hence, the correct answer is
D
