in Quantitative Aptitude recategorized by
417 views
1 vote
1 vote

How many pair of natural numbers are there, the differences of whose squares is $45$ ? 

  1. $1$
  2. $2$
  3. $3$
  4. $4$
in Quantitative Aptitude recategorized by
12.0k points
417 views

2 Answers

0 votes
0 votes
Best answer
Let first number be $x$, and the second number be $y.$

$(x^{2} - y^{2}) = 45$
$\implies (x - y)(x + y) = 45$

The factors of $45$ are $15, 3, 9, 5, 1$ and $45$

Hence, the possible pairs of numbers are $(9,6), (7,2)$ and $(23,22).$

$\therefore$ The number of such pairs $= 3.$

The correct answer is $(C).$
selected by
12.0k points
0 votes
0 votes
$\textrm{3 pair,9 and 6 or 7 and 2 or 23 and 22. }$
4.7k points
Answer:

Related questions

Quick search syntax
tags tag:apple
author user:martin
title title:apple
content content:apple
exclude -tag:apple
force match +apple
views views:100
score score:10
answers answers:2
is accepted isaccepted:true
is closed isclosed:true