The larger of two numbers is twice the smaller. If the sum is 54 find the numbers

So there are 2 numbers

pretend the smaller number is x, so the larger number must be 2x because it's twice as large

so 2x+x equals 54

simplifies to 3x=54

x = 18

the smaller number is 18 and the larger one is 36 (because 36 is 18 x 2)