Question

A number consists of two digits whose sum is 11. If 27 is added to the number, then the digits change their places. What is the number ?
(a) 65
(b) 83
(c) 92
(d) 47

Answer 1

(d) 47
The two digits in the number 47 is 4 and 7. The sum of those two digits is 11. If 27 was added to 47 it would equal 74. The digits 4 and 7 changed places as the 4 moved to the ones spot while 7 moved to the tens spot.

Answer 2

Answer:

47

Step-by-step explanation:

Let the ten's digit be x. Then, unit's digit = (11 - x).       So, number = 10x + (11 - x) = 9x + 11.       Therefore (9x + 11) + 27 = 10 (11 - x) + x ⇔ 9x + 38 = 110 - 9x ⇔ 18x = 72 ⇔ x = 4.       Thus, ten's digit = 4 and unit's digit = 7.       Hence, required number = 47