A certain number of two digits is three times the sum of its digits If 45 is added to the number the...........

Quantitative Aptitude (CDS) Number System

A certain number of two digits is three times the sum of its digits. If 45 is added to the number, then the digits will be reversed. What is the sum of the

squares of the two digits of the number?

छोटे Courses बड़े Results

Master Number System

Prepare through Micro-courses

Try Now

Explanation:

Let the digit number be 10x + y.
According to the to the question 10x + y = 3(x +y)
⇒ 10x + y − 3x − 3y = 0
⇒ 7x − 2y = 0 … … (??)
According to question
⇒ (10x + y) + 45 = 10y + x
⇒ 10x + y + 45 = 0
⇒ x − y = −5
Now, solving equation (i) and (ii) we get
x = 2 and y = 7
Digit 10×2 + 7 = 27
Sum of the squares of digits = 22 + 72=53