Problema Solution
10. In a 2-digit number, the number in the unit’s place is 4 more than the number in the ten’s place. If the digits of the number are reversed, the new number is 6 more than thrice the original number. Find the original number.
Answer provided by our tutors
let
x is the number in the ten's place
y is the number in the unit's place
the 2-digit number can be written as 10x + y
the number in the unit’s place is 4 more than the number in the ten’s place
y = x + 4
If the digits of the number are reversed, the new number is 6 more than thrice the original number
10y + x = 6 + 3(10x + y)
by solving the system of equations
y = x + 4
10y + x = 6 + 3(10x + y)
we find
x = 1
y = 5
click here to see the step by step solution of the system of equations
10x + y = 10*1 + 5 = 15
the original number is 15.