Answer= 4 hours.
The first pipe can fill one pool in nine hours. So in one hour, it can fill 1/9th of the pool. Same with the other pipe, it can fill 1/6th of the pool in other hour.
So 1/9 + 1/6 would represent the first hour of filling the pool. Since 1/9 + 1/6 = .277.. , 27% of the pool is filled. Repeat this until you get to 100% (full pool).
First hour, 1/6 + 1/9 = .27
Second hour, 2/6 + 2/9 = .5
Third hour, 3/6 + 3/9 = .83
Fourth hour, 4/6 + 4/9 = 1.11
So in 4 hours, the pool will be filled.
Simplify the numerator and denominator first:
5/8 + 3/4 = 11/8
-2/3 - 5/6 = -3/2
Now you have 11/8 / -3/2
When dividing two fractions change division to multiplication and flip the second fraction over:
11/8 x -2/3 = 11 x -2 / 8 x 3 = -22/24
-22/24 reduces to -11/12
The answer is -11/12
Answer:
8
Step-by-step explanation:
a = 4
b = 3
4 / a
= 4 / 4
= 1
b / 3
= 3 / 3
= 1
6 + 4 / a + b / 3
= 6 + 1 + 1
= 8
2/25 = x/80....2 chaperones to 25 students = x chaperones to 80 students
cross multiply because this is a proportion
(25)(x) = (2)(80)
25x = 160
x = 160/25
x = 6.4......so basically, since u cant have .4 of a person, we need to round up, so the school needs 7 chaperones for 80 students