Answer:
7040
Step-by-step explanation:
C= 2000
B = 20/100 x 2000 = 400 + 2000 = 2400
A= 10/100 x 2400 = 240+2400= 2640
2000 + 2400 + 2640 = 7040

get their LCD, like you'd with any other fractions, and add them up
Answer:
250
Step-by-step explanation:
There is a 200 start up cost plus 50 per month
Cost = 200 + 50m where m is the number of months
We have 1 month
Cost = 200 +50(1)
Cost = 250
38 meters long is the answer