Question

When x equals 8 y equals 20 find y when x equals 42

Answer 1

We know that when x=8, y=20, we do try to find a number close to x=42 which is
8=20   16=40   24=60   32=80   40=100.
So the closest number to 42 is 40. Now we do this:
8/4=2
20/4=5   We now know that every x=2 is y=5. So do this now:
40+2=100+5
42=105
Therefore, when x=42, y is equal to 105.

Answer 2

The relation between the numbers is 2:5 so it would be 2x and 5y and you plug in the numbers. When x=42 which is 2(21) then y would be 5(21) which equals 105 :-)