Question 622052
I don't know what the second part of you question is asking, but I can help you solve for the two numbers.
To solve this problem, you want to write two equations using what you know, and then combine them into one equation and solve.
First, you know that the sum of two numbers is 20. So:
x + y = 20
Next, you know that one number (let's just say x) is 3 times larger than the second number (y). In other words, you have to multiply y by 3 to get x. So:
x = 3y
Now plug the second equation into the first equation for x and solve:
x + y = 20
(3y) + y = 20
4y = 20
y = 5
So you know one number equals 5.  To find the other number, plug this value into the first equation:
x + y = 20
x + 5 = 20
x = 15
So your two numbers are 5 and 15.

What are the answers they give you?