The sum of 3 numbers is 61. The second number is 5 times the first. While the 3rd is 2 less then the first. How do you find the numbers?

1 Answer
Oct 18, 2015

9, 45, and 7

Explanation:

Let's say that your numbers are x, y, and z.

The first thing to write down is that their sum is equal to 61

x + y + z = 61" " " "color(purple)((1))

Next, you know that the second number, y, is five times bigger than the first, x. This is equivalent to saying that you need to multiply x by 5 to get y

y = 5 * x" " " "color(purple)((2))

Finally, you know that if you subtract 2 from x you get the z

z = x - 2" " " "color(purple)((3))

Use equations color(purple)((2)) and color(purple)((3)) to find the value of x in equation color(purple)((1))

x + 5x + x - 2 =61

7x = 63 implies x = 63/7 = color(green)(9)

Now take this value of x and find y and z

y = 5 * (9) = color(green)(45)

z = (9) - 2 = color(green)(7)

The three numbers are 9, 45, and 7.