Simple maths equation, please help?

Question

I know the answer, but I don't know how to arrive at the answer.

How many minutes is it before noon if 56minutes ago it was three times as many minutes past 10am?

The answer is 16, but step by step  how is it worked out?

Ashtray · Accepted Answer

I am going to represent time on a scale of 0 to 120 since there are 120 minutes between 10am and noon.

The time is currently x.  The time from noon is 120 - x.

x-56 is the time 56 minutes ago which is 3 times the distance from noon, so use the equation:

x-56 = 3(120-x)

x - 56 = 360 - 3x

solve for x :      4x = 416  
x = 104


noon would be 120 and it is currently 104.   120-104 = 16

Druisse · Answer

let x = number of minutes before noon
Given: noon = 12 hours = 720 minutes
        10 am = 10 hours = 600 minutes

720 - x = 600 + 3x + 56
-x - 3x = 600 + 56 - 720
-4x = -64
x = 16

Anonymous · Answer

Im not quite sure. I think it may be a matter of guess and check.

Simple maths equation, please help?

3 Answers