If a and b represent positive single digits in the correctly

This topic has expert replies
Moderator
Posts: 7187
Joined: Thu Sep 07, 2017 4:43 pm
Followed by:23 members

Timer

00:00

Your Answer

A

B

C

D

E

Global Stats

22
a3
+4b
___
90

If a and b represent positive single digits in the correctly worked computation above, what is the value of the two digit integer ba?

A. 10
B. 15
C. 25
D. 51
E. 52

OA E

Source: Manhattan GMAT

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 16207
Joined: Mon Dec 08, 2008 6:26 pm
Location: Vancouver, BC
Thanked: 5254 times
Followed by:1268 members
GMAT Score:770

by Brent@GMATPrepNow » Sat Aug 04, 2018 4:56 am
BTGmoderatorDC wrote:22
a3
+4b
___
90

If a and b represent positive single digits in the correctly worked computation above, what is the value of the two digit integer ba?

A. 10
B. 15
C. 25
D. 51
E. 52
Units digits first....
2 + 3 + b yields a sum with units digit 0
So, b = 5

So, the top number and bottom number are now 22 and 45
We have:
22
a3
+45
___
90

22 + 45 = 67
So, we have: 67 + a3 = 90
Subtract 67 from both sides to get: a3 = 23
So, a = 2

What is the value of the two digit integer ba?
ba = 52

Answer: E

Cheers,
Brent
Brent Hanneson - Creator of GMATPrepNow.com
Image

GMAT/MBA Expert

User avatar
Elite Legendary Member
Posts: 10392
Joined: Sun Jun 23, 2013 6:38 pm
Location: Palo Alto, CA
Thanked: 2867 times
Followed by:511 members
GMAT Score:800

by [email protected] » Sun Aug 05, 2018 6:22 pm
Hi All,

We're told that A and B each represent positive single DIGITS in the correctly worked calculation: 22 + A3 + 4B = 90 (reminder: each value is a 2-digit number). We're asked for the value of the two digit integer BA. This question can be solved in a couple of different ways. You can do the basic Arithmetic (as Brent has shown) or you can TEST THE ANSWERS. From the five choices, we know that the value of B is either 1, 2 or 5 and the value of A is 0, 5, 1 or 2. Once you determine the value of B, there are only two possible options for A...

Final Answer: E

GMAT assassins aren't born, they're made,
Rich
Contact Rich at [email protected]
Image