Answer:

Step-by-step explanation:
We are given that

Side of base=4 cm
l=w=4 cm
Height,h=12 cm
We have to find the rate at which the water level rising when the water level is 4 cm.
Volume of pyramid=


Substitute the value

Differentiate w.r.t t

Substitute the values


Find a common multiple in between the denominators.
10 and 3 and 5 -> the least common multiple is 30.
Change all the denominators to 30 by multiplying the top and bottom by the same number.
9/10=27/30
1/3=10/30
1/5=6/30
Subtract!
27/39-10/30-6/30=11/30
The answer is 11/30
Hope this helps!
Answer:
22
Step-by-step explanation:
The easiest way to do this is to multiply the number you got right by 1+ the percent you got wrong. In this case it would be 1+.18. If you multiply 18 by 1.18 you get 21.24. Because you cant have part of a question you need to round up. To check you can divide 18 by 22 and you get 81.81. I hope this helps!