CAT 2021 Question Paper | Quant Slot 2

CAT 2021 Quant was dominated by Arithmetic followed by Algebra. In Arithmetic, the questions were dominated by topics like Speed-time-distance, Mixture and Alligations. This year, there was a surprise. The questions from Geometry were relatively on the lower side as compared to the previous years. There were 8 TITA Qs this year. Overall this section was at a medium level of difficulty.

Question 3 : Consider the pair of equations: x² - xy - x = 22 and y² - xy + y = 34. If x > y, then x - y equals

Video Explanation

Explanatory Answer

x² - xy - x= 22.
y² - xy + y= 34.
If we add these two equations,we get
(x - y)² - x + y = 56 or (y - x)² - x + y = 56
Since we need to find for x > y, we should take (x - y)² - x + y = 56
(x - y)² - (x - y) = 56
(x - y) (x - y - 1) = 56
If we take x - y = n, then we will boil down to n (n - 1) = 56
Therefore, x - y = 8

The question is " Consider the pair of equations: x² - xy - x = 22 and y² - xy + y = 34. If x > y, then x - y equals "

Hence, the answer is '8'

Choice A is the correct answer.