In a two-digit number, the digit in the unit's place is four times the digit in ten's place and sum of the digits is equal to 10. Find the number.

Correct option is C

Let the unit place digit be x and ten’s place digit y
As per the question
4y = x …………….(1)
x + y = 10 …………………(2)
from equation (1) and (2)
5y = 10
y = 2
x = 8
Therefore, the number is 28.