A particular project can be completed by six people working eight hours a day for twenty days. To speed up completion of the project, eight workers were put on the project to complete the project in twelve days. How many hours a day must the workers put each day, in order to complete the job on time?

10

Step-by-step explanation:

10 because you have to do the first problem first. 6 people × 8 hours = the total of 48 then times the days (20) and get the answer of 960. Then what you do is 960 and divide it by 12 and get 80 then divide that by 8 getting the answer of 10

second option

step-by-step explanation:

the measures of a triangle equal 180. use that to find x.

2x+3x+4x=180

9x=180

9x/9=180/9

x=20

now you know x, you know angle a is 40°, angle b is 60°, angle c is 80°.

because angle a is 40°, the first option doesn't work.

because angle b is 60°, the second option does work.

when you add angle a and b, you get 100°. complementary means it equals 90°, so the third option doesn't work.

when you add angle a and c, you get 120°, which is not 100.