Question

In a two digit number. The units digit is thrice the tens digit. If 36 is added to the
number, the digits interchange their place. Find the number.

Answer 1

Given,

In a two digit number, the units digit is thrice the tens digit.

Let the number be "ab"

⇒ b = 3a

Therefore, we have,

ab = 10a+b

When 36 is added to the  number, the digits interchange their place.

⇒ 10a + b + 36 = 10b + a  

substituting b = 3a, we get,

10a + 3a + 36 = 10(3a) + a

10a + 3a + 36 = 30a + a

13a + 36 = 31a

36 = 31a - 13a

36 = 18a

a = 36/18

∴ a = 2

b = 3 × 2

∴ b = 6

Therefore, the required number is 26

Verification:

We have,

ab = 26

26 + 36 = 62

Answer 2

Step-by-step explanation:

In a two digit number, the unit’s digit is thrice the ten’s digit. If 36 is added to the number, the digits interchange their place, then the number is