Let x = the amount of time that the third person needs to work on the job to add up to one
1 = 1/2 + 1/3 + x
1 - 1/2 - 1/3 = x
To subtract the fractions we need to put them all over a common denominator. Let's use 3*2 = 6 as the denominator; so 1 = 6/6, 1/2 = 3/6, 1/3 = 2/6:
6/6 - 3/6 - 2/6 = x
1/6 = x
The third person must work 1/6 time on the project.
360/60 = 6
6 degrees every second
6*20 = 120 degrees
120 degrees after 20 seconds
6 * 45 = 270
270 degrees after 45 seconds
Hope I helped!
Let me know if you need anything else!
~ Zoe
5a + s = 2662
a + s = 1198
4a = 1464
a = 366
5(366) + s = 2,662
1830 adult tickets sold
2662 - 1830 = 832
832 student tickets sold
80/400 as a decimal is 0.2