Initial number of students: 220
Final number of students : 180
Multiply the initial number of students (220) by the percentage change in decimal form (divided by 100) - That expression must be equal to 180.
220 x = 180
Solve for x:
x=180/220
x= 0.818181
multiply by 100
81,81 %
100%-81,81% = 18.18%
Percent change: 18.18%
Answer:
It takes 20 weeks to empty the lake
Step-by-step explanation:
Some rate, let's call it
empties the lake in 10 weeks and a river (with rate
can fill the lake in 20 weeks. The idea behind the solution of this type of problem is always set the rate to the same units. Let's see this:
which implies that this rate empties 0.1 of the lake per week, thus,
.
Using the same idea, we can obtain that the filling rate of the river is:

Since both rates are acting at the same time, the total rate of flowing water (either in or out the lake) would be given by:
, which means that the lake is being empty at a rate of -0.05 week and using the rule of three:

Thus, It takes 20 weeks to empty the lake.
Answer:
(2.5,3.5) ywww
Step-by-step explanation:
"4600" (and any subsequent words) was ignored because we limit queries to 32 words.
Answer:
It will take her 1 hour and 40 minutes.
Step-by-step explanation
12 / 2 = 6
1 hour she makes six necklaces
She makes one necklaces every 10 minutes
10 minutes multiplied by 10 equals 1 hour and 40 minutes.
Hope this Helps!