Q15 of 266 Page 4

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.

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.


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