## 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

### In the addition problem above, the number $$*$$ must be?

by Gmat_mission » Thu Aug 20, 2020 9:26 am

00:00

A

B

C

D

E

## Global Stats

In the addition problem above, the number $$*$$ must be?

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

Source: Official Guide

### GMAT/MBA Expert

GMAT Instructor
Posts: 16084
Joined: 08 Dec 2008
Location: Vancouver, BC
Thanked: 5254 times
Followed by:1267 members
GMAT Score:770

### Re: In the addition problem above, the number $$*$$ must be?

by [email protected] » Fri Apr 08, 2022 5:34 am
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

Source: Official Guide
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!