In the addition problem above, the number \(*\) must be?

This topic has expert replies
Legendary Member
Posts: 1622
Joined: 01 Mar 2018
Followed by:2 members

Timer

00:00

Your Answer

A

B

C

D

E

Global Stats

question.JPG
In the addition problem above, the number \(*\) must be?

(A) 5
(B) 6
(C) 7
(D) 8
(E) 9

Answer: B

Source: Official Guide

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 16084
Joined: 08 Dec 2008
Location: Vancouver, BC
Thanked: 5254 times
Followed by:1267 members
GMAT Score:770
Gmat_mission wrote:
Thu Aug 20, 2020 9:26 am
question.JPG

In the addition problem above, the number \(*\) must be?

(A) 5
(B) 6
(C) 7
(D) 8
(E) 9

Answer: B

Source: Official Guide
STRATEGY: Upon reading any GMAT Problem Solving question, we should always ask, Can I use the answer choices to my advantage?
In this case, we can easily replace each * with each answer choice until we find the one that creates the correct addition.
Now let's give ourselves up to 20 seconds to identify a faster approach.
In this case, we can also assign variables to the missing digits, but I can already see that testing the values will be super fast.
So, let's go with that...


When we replace each * with 5, the addition doesn't work.
When we replace each * with 6, the addition works!

Image

Answer: B
Brent Hanneson - Creator of GMATPrepNow.com
Image