Question

One number is 800 less than 3 times the other, and their sum is 1,200. Find the numbers. Which of the following equations can be used to solve the problem if the smaller number is x?

1. 2x - 800 = 1,200
2. 3x - 800 = 1,200
3. 4x - 800 = 1,200

Answer 1

Option (3) 4x - 800 = 1200

Answer 2

Option (3) 4x - 800 = 1200

Explanation:

Let the numbers are x and y

By the statement "One number is 800 less than 3 times of other."

y = 3x - 800 ----------(1)

By another statement " Sum of these numbers is 1200."

x + y = 1200

y = (1200 - x)-------(2)

Now put the value of y from equation (2) to equation (1)

1200 - x = 3x - 800

1200 = x + 3x - 800

4x - 800 = 1200

Therefore, Option (3) 4x - 800 = 1200 is the answer.