C. −6, is the best option
Answer:

Step-by-step explanation:
Let c represents child bikes and a represents adult bikes.
Given : Each child bike requires 4 hours to build and 4 hours to test. Each adult bike requires 6 hours to build and 4 hours to test.
With the number of workers, the company is able to have up to 120 hours of building time and 100 hours of testing time for a week.
Then, the required system of inequality :-

If company make 10 child bikes and 12 adult bikes in the week.
Then Put c=10 and a=12 bikes in (1) and (2).
⇒Bike order meets the restrictions
⇒Bike order meets the restrictions
Hence, the system of inequality best explains whether the company can build 10 child bikes and 12 adult bikes in the week.

For number 2 it's would be 12.8
Sorry I don't have time for number 3
Answer:
1.20
Step-by-step explanation:
Because .2 is in the tenths place and 0 is the hundredths so you round the hundredths to the tenths and since its 0 then it stays the same.
Answer:
108 : 145
Step-by-step explanation:
253 - 108 = 145
Ratio of those who receive 2 weeks of paid vacation is 108
Ratio of those paid vacation is not 2 weeks is 145
108 : 145