Correct Answer - Option 4 : 47
Given:
A number consists of two digits whose sum = 11
If 27 is added to the number then the digits change their places.
Calculation:
Let the two digits be x & y.
X + y =11
Y=11 - x (1)
Numbers is = 10x + y
10x + y + 27 = 10y + x
⇒ 10x +11 - x + 27 = 10 (11 - x) + x
⇒ 10x +11 - x + 27 = 110 - 10 x + x
⇒ 9x + 10x - x = 110 - 11 - 27
⇒ 18x = 110 - 38
⇒ 18 x = 72
⇒ x = 4
then , put the value of x, Y= 11 - 4 (1) = 7
y = 7
∴ the number is 47
