Skip to content
Related Articles

Related Articles

Improve Article
Save Article
Like Article

GATE | Sudo GATE 2020 Mock III (24 January 2019) | Question 8

  • Last Updated : 22 Jan, 2020

A 4-digit number of the form aabb is a perfect square. What is the value of a – b ?
(A) 3
(B) 2
(C) 1
(D) 4


Answer: (A)

Explanation: A number of the form aabb has to be a multiple of 11.
So, it is the square of either 11 or 22 or 33 or…so on up to 99.

882 = 7744 

This is the only solution possible.
Most of these trial and error questions need to be narrowed down a little bit before we can look for the solution.
That narrowing down is critical. In this case, we should look for multiples of 11.

Attention reader! Don’t stop learning now.  Practice GATE exam well before the actual exam with the subject-wise and overall quizzes available in GATE Test Series Course.

Learn all GATE CS concepts with Free Live Classes on our youtube channel.

Hence the answer is “3”.

Option (A) is correct.

Quiz of this Question

My Personal Notes arrow_drop_up
Recommended Articles
Page :

Start Your Coding Journey Now!