Answer:
number 3
Step-by-step explanation:
The answer is 67% because it rounds to 67%
A=1/10, b=1/12, c=1/15 (these are the rates for each worker...)
1.)
2(1/10)+4(1/12)+t/15=1
1/5+1/3+t/15=1
(3+5+t)/15=1
3+5+t=15
8+t=15
t=7
So it would take c 7 hours to finish the job.
2.)
1/40-1/60
(3-2)/120
1/120
The drain rate is 1/60. So you will need to find t when the tank is empty, while starting at 2/3 capacity...
2/3-t/60=0
(40-t)/60=0
40-t=0
t=40
It would take 40 minutes to empty the tank when it is 2/3 full.
Answer: D
Step-by-step explanation:
Substitute values for x until they all work.
A. y = 2 x 2 + 5 = 9 fail
B. y = 2 x 2 - 6 = -2 fail
C. y = -2 x 2 - 5 = -9 fail
D. y = -0.5 x 2 - 5 = -6 ok
y = -0.5 x 5 - 5 = -7.5 ok
y = -0.5 x 6 - 5 = -8 ok
