On n-tuples times a number

Treat the first number as x and the second number y. Since x is twice y, x can be denoted as 2y. Now, the sum of x and y is x+y, which can be renamed as 2y+y, which is equal to 3y. The first sentence in the problem will give you 10(3y), which equals 30y. Now, plugging in the supposed product, which is 360, will give you 30y=360, leading you to the fact that y=360/30, which is 12.

suppose, the first number is = $x$

so, the second number is= $\frac{x}{2}$

now,

$10(x+\frac{x}{2})=360$

or, $(\frac{x+2x}{2})=36$

or, $3x=72$

or, $x=24$

so, the second number is= $12$

Let the second number be x then the first number be 2x. then 10(x+2x) = 360 or 3x = 36 which gives x = 12