Question

What is the number?

I.

The sum of the two digits is 8. The ratio of the two digits is 1 : 3.

II.

The product of the two digit of a number is 12. The quotient of two digits is 3.

Answer 1

2 and 6

Explanation:

Let's assume, the first digit (ten's place) is x and the second one (unit's place) is y

Let's write 2 equations according to the given information and put them in a system:

{x / y = 3,

{xy = 12;

Let's make x the subject from the 1st equation (it doesn't matter which equation or term (x or y) you choose):

x = 3y

Replace x in the 2nd equation with its new value from the 1st one:

3y * y = 12

`3 {y}^(2) = 12`

Divide both parts by 3 to make x^2 the subject:

`{y}^(2) = 4`

`y > 0`

`y = √(4) = 2`

x = 3 * 2 = 6