Question 46 Problem Solving 2018 GMAT Official Guide:
In this question: in the video explanation; when we take examples , 23+32 = 55, so 55 is also not divisible by 9 right, so in first example itself we eliminate answer options of 6,9,10,14 and left with 9.
In video it is mentioned that for 23+32= 55, we have two answer options , ie 9 and 11. Please advice. Thank you
Thanks for pointing out the error. Yes, the example of x=23 and y=32 would give you the correct answer because that number is only divisible by 11. I will make the correction.
Are you referring to the $10$ that I used in writing a two digit integer $tu$, where $t$ is the tens digit and $u$ is the units digit, and the value of the integer is equal to $10t+u$?
georg vilshofen says
Note this is labeled as #46 from OG 2018, though the video correctly covers #63 from 2019.
georg vilshofen says
OK, I see; it’s the same problem as in OG 2018, with a diff number.
Jayita Ghosh says
Question 46 Problem Solving 2018 GMAT Official Guide:
In this question: in the video explanation; when we take examples , 23+32 = 55, so 55 is also not divisible by 9 right, so in first example itself we eliminate answer options of 6,9,10,14 and left with 9.
In video it is mentioned that for 23+32= 55, we have two answer options , ie 9 and 11. Please advice. Thank you
GMAT Quantum says
Hi Jayita,
Thanks for pointing out the error. Yes, the example of x=23 and y=32 would give you the correct answer because that number is only divisible by 11. I will make the correction.
Dabral
ian says
Why did u take 10? Why not any number in the first approach. Please reply.
GMAT Quantum says
Are you referring to the $10$ that I used in writing a two digit integer $tu$, where $t$ is the tens digit and $u$ is the units digit, and the value of the integer is equal to $10t+u$?