Seven times a two-digit number is equal to four times the number obtained by reversing the digits. If the difference between the digits is 3. Find the number.

Question

Philoid · Accepted Answer

Let the one’s digit be ‘a’ and ten’s digit be ‘b’.

Given, seven times a two-digit number is equal to four times the number obtained by reversing the digits.

⇒ 7(10b + a) = 4(10a + b)

⇒ 66b = 33a

⇒ a = 2b ----- (1)

Also, difference between the digits is 3

⇒ a – b = 3

⇒ 2b – b = 3

Thus, b = 3

⇒ a = 2 × 3 = 6

Number is 36.