Problema Solution
The tens digit of a two-digit number is 1 more than three times the unit digit. The sum of the number and the number formed by reversing the digits is 99. Find the number
Answer provided by our tutors
t = 10's digit
u = 1's digit
t + u = 11
10u + t = 45 + (10t + u)
This second equation is the tricky part. It says that the VALUE of the reversed number (10 times the unit's digit added to the ten's digit itself) is equal to 45 more than the original number (10 times the ten's digit added to the unit's digit)
Combine like terms: 9u - 9t = 45
Solve by elimination:
9u - 9t = 45
-9u -9t = -99
-18t = -54
t = 3, u = 8
Original number is 38.
EDIT: xjroll, I teach math for a living, so I think I should remember this. :D
Which reminds me... I'm not getting paid for this! Time to go home! :)
1 year ago