Answer:
6.5%
Step-by-step explanation:
I = prt
5616 = 7200 × r × 12
r = 5616/(7200 × 12)
r = 0.065
r = 6.5%
Suppose the larger pump alone can empty the tank in L hours, and the smaller pump can finish the job in S hours, then each hour the large pump empties 1/L portion of the tank, and the small pump empties 1/S per hour
Working together for three hours, they empty the whole tank, which is 100% of it, so 3/L+3/S=100%=1
Larger pump can empty the tank in 4 hours less than the smaller one, so L=S-4
replace L: 3/(S-4)+3/S=1
Make the denominator the same to solve for:
3S/[S(S-4)] +3(S-4)/[S(S-4)]=1
(3S+3S-12)/[S(S-4)]=1
(3S+3S-12)=[S(S-4)]
S^2-10s+12=0
use the quadratic formula to solve for S
S is about 8.6
The answer is not whole hour.
Answer:
1. 64
2. 72 square feet
3. 31.5 square feet
Step-by-step explanation:
For the first one use the equation A=bh.
Plug in your values: A=12.8*5.
Solve: A=64
For the second one multiply 8*3 which gives you 24. Next multiply that by 3 to give you 72 square feet.
For the third one multiply 9 by 3.5 to get 31.5 square feet.
The answer if you need helo with math like this come to me -25
