Question

The tens digit exceeds the units digit by 3. If the units digit is r what is the value of the number ?

Answer 1

r=6

Explanation:

Answer 2

we have a number of two digits, ab.

The tens digit is a. the unit digit is b.

We know that:

a = 3 + b

b = r.

We can replace the second equation in the first one, and get:

a = 3 + r.

Then we have that our number is:

(3 + r) for the tens digit, and r for the unit digit.

Now, remember that the maximum possible digit is 9.

then the maximum possible value of r comes from.

3 + r = 9

r = 9 - 3 = 6.

Then the possibles values of r are: 0, 1, 2, 3, 4, 5 and 6.