# [SOLVED]Find the Number Satisfying the Given Conditions

#### karush

##### Well-known member
The sum of the digits of a two-digit number is $12$ The number is $13$ times the tens digit. Find the number

well from $3+9=12$ we can see that the number would be $39$ which is $3\times 13$

but again I had trouble knowing how to set this up

In that $10t+u=12$ how do you set up $13t=$

mahalo much...

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#### MarkFL

Staff member
I would let A be the ten's digit and B be the one's digit. We are then told:

(1) $\displaystyle A+B=12$

$\displaystyle 10A+B=13A$ or:

(2) $\displaystyle B=3A$

Now substitute for B into (1) using (2) to solve for A, then from (2) you will have B.

What number do you find?

#### karush

##### Well-known member
does it really have to be this easy....

A=3 then B=9

Oh and yes, Honolulu is a very nice place to live, me 12 years +

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