Answer:
We have to use rounding or compatible numbers to estimate the difference of 762-332
Now rounding here can be done like rounding the tens place or the hundreds place and each will produce different result.
Rounding to tens place :
762=760
332=330
Difference =
Rounding to hundreds place :
762=800
332=300
Difference =
12/7 = 20/x
12x = 140
x = 140/12 = 35/3 = 11.67
so radius of the large cone = 11.67 ft
Volume = 1/3 πr^2h
= 1/3(3.14)(11.67)^2(20)
= 2850.88
Answer is B. 2850.70 ft^3