The correct option is B 47, 74
Let the digit at the units place be x and the digit at the tens place be y. Then the number = 10y + x
From the condition given in the equation we have,
(10y + x) + (10x + y) = 121
⇒ 11(x+y)= 121 ⇒ x + y = 11
and, x - y = 3 [ Differences of the units and the tens digits is 3]
Thus, we have the following sets of simultaneous equations
x + y = 11 ...(1)
x - y = 3 ...(2)
On solving equations (1) and (2), we get 2x = 11 + 3
⇒ x = 7
Substituiting x = 7 in equation (1), we get
7 + y = 11 ⇒ y = 4
∴ When x = 7, y = 4.
Hence, the number = 10y + x = 10 × 4 + 7 = 47 and
reverse of the number = 10x + y = 10 × 7 + 4 = 74
Hence, the required numbers are 47 and 74.