9514 1404 393
Answer:
√629 ≈ 25.08
Step-by-step explanation:
The distance formula is useful for this.
d = √((x2 -x1)² +(y2 -y1)²)
d = √((-12 -13)² +(6 -8)²) = √(625 +4) = √629 ≈ 25.08
The distance between the points is about 25.08 units.
kids at zoo, k = 325
percentage boys, b = 64%
percentage girls, g = 100 - b = 36%
number of girls = 325 × 36% = 117
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.
