Posted by **Joe Mhar Plaza** on Thursday, January 6, 2011 at 10:34pm.

The sum of the of a two-digit number is 15. One third of the number diminished by 12 is 17. Find the number.

- Exploring mathematics elementary algebra -
**Reiny**, Thursday, January 6, 2011 at 10:52pm
Did you mean the "sum of the digits of a two-digit number is 15" ?

if so, then

let the unit digit be x

let the tens digit be y

so the value is 10y + x

"One third of the number diminished by 12 is 17"

---> (1/3)(10y+x) - 12 = 17

(1/3)(10y+x) = 29

multiply by 3

10y+x = 87

x = 87 - 10y

also x+y = 15

by substitution:

87-10y + y = 15

-9y = -72

y = 8

x = 87 - 80 = 7

the number is 87

check the properties stated.

## Answer this Question

## Related Questions

- Exploring mathematics elementary algebra - The units digits of a two-digit ...
- exploring mathematics elementary algebra - the sum of the digits of a two-digit ...
- tres ninos school - exploring mathematics elementary algebra....the sum of the ...
- Exploring mathematics elementary algebra - the units of a two-digit number ...
- Exploring mathematics elementary algebra - The tens digit of a two-digit number ...
- Algebra math. - 1) the sum of the digits of a two digit number is 9. The value ...
- Mathematics - There is a two-digit number such that the sum of its digit is 6 ...
- Mathematics - There is a two-digit number such that the sum of its digit is 6 ...
- maths - Find the sum of all 3-digit positive numbers N that satisfy the ...
- 8th Grade Algebra - These are extra credit questions, and I just want to know ...