McGraw-Hill Education GRE 2019

S T E P 1: Choose values for the variables in the question. What values should

you choose for a and b? You can choose anything that does not violate the rules

outlined in Step 1 of the previous section, but keep in mind that you want c to

be an integer. If c = an integer, then 11c must be a multiple of 11. Thus to yield an

integer for c, you should choose values for a and b that will sum to a multiple of 11.

Let’s choose 9 for a and 13 for b. Those values sum to 22, which is a multiple of 11.

Now use these values to solve for c:

a + b = 11c

9 + 13 = 22 = 11c

11 c = 22

c = 2

So your values are a = 9, b = 13, c = 2.

STEP 2: Answer the question using the values you chose for the variables. What

is the average of 9, 13, and 2?

9 + 13 + 2

3 =

24

3 = 8

Circle the “goal”: 8

STEP 3: Plug the values into the choices and see which choice yields a value that

matches your goal. Here’s the original question again:

If a + b = 11c, what is the average of a, b, and c, in terms of a and b?

A 3 c

B 3 c + 1

C 4 c

D 5 c

E 5 c − 1

Now substitute 2 for c in all the choices and identify which choice matches

the target of 8.

A 3(2) = 6 → No

B 3(2) + 1 = 7 → No

C 4(2) = 8 → Ye s

D 5(2) = 10 → No

E 5(2) – 1 = 9 → No

The only choice that yields a value that matches the target is C.

152 PART 3 ■ GRE QUANTITATIVE REASONING

02-GRE-Test-2018_107-172.indd 152 13/05/17 11:06 am