Answer:
Step-by-step explanation:
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:
walks dogs for 3 hours on Saturday and 4 hours on
Sunday. She calculates her total pay to be $57.75.
Which equation could be used to check the reasonableness of her total?
Step-by-step explanation: concept
If this is what I think it means, then a number N is 3. Otherwise I don’t entirely understand.
Answer:
9km
Step-by-step explanation:
If the distance on the map of 8cm between her house and school is equal to 12km actual distance. This means that each cm on the map represent 1.5km in actual distance (12/8=1.5).
This means that D is equal to 9km actual distance, because if each cm represents 1.5km, then 6 cm represents 9km (6x1.5=9).
Hope this helped!