Given:


To find:
The rate of change in volume at 
Solution:
We know that, volume of a cone is

Differentiate with respect to t.
![\dfrac{dV}{dt}=\dfrac{1}{3}\pi\times \left[(r^2\dfrac{dh}{dt}) + h(2r\dfrac{dr}{dt})\right]](https://tex.z-dn.net/?f=%5Cdfrac%7BdV%7D%7Bdt%7D%3D%5Cdfrac%7B1%7D%7B3%7D%5Cpi%5Ctimes%20%5Cleft%5B%28r%5E2%5Cdfrac%7Bdh%7D%7Bdt%7D%29%20%2B%20h%282r%5Cdfrac%7Bdr%7D%7Bdt%7D%29%5Cright%5D)
Substitute the given values.
![\dfrac{dV}{dt}=\dfrac{1}{3}\times \dfrac{22}{7}\times \left[(120)^2(-2.1) +175(2)(120)(1.4)\right]](https://tex.z-dn.net/?f=%5Cdfrac%7BdV%7D%7Bdt%7D%3D%5Cdfrac%7B1%7D%7B3%7D%5Ctimes%20%5Cdfrac%7B22%7D%7B7%7D%5Ctimes%20%5Cleft%5B%28120%29%5E2%28-2.1%29%20%2B175%282%29%28120%29%281.4%29%5Cright%5D)
![\dfrac{dV}{dt}=\dfrac{22}{21}\times \left[-30240+58800\right]](https://tex.z-dn.net/?f=%5Cdfrac%7BdV%7D%7Bdt%7D%3D%5Cdfrac%7B22%7D%7B21%7D%5Ctimes%20%5Cleft%5B-30240%2B58800%5Cright%5D)


Therefore, the volume of decreased by 29920 cubic inches per second.
Answer: Third option.
Please, see the detailed solution in the attache file.
Thanks
d. Adjustments
Studen loan interests and IRA contributions are deductions found under the heading of ADJUSTMENTS TO INCOME to compute for the Adjusted Gross Income or AGI.
Standard deductions are those based on the filing status of the individual and not his total itemized deductions. Regardless of the actual expenses incurred by an individual, he can claim a standar deduction if he is single, head of household, married filing separately, married filing jointly, qualifying widow(er). at the time he files for his federal tax return.
taxable income is the income left from all the necessary deductions.
For example: Gretchen's income => $56,750
less: Adjustments to income
student loan interest $1,200
IRA Contribution 3,000 - 4,200
===========
Taxable income $52,550
X - Jack's age
y - Susan's age
Jack is 27 years older than Susan.

In 5 years he will be 4 times as old as she is.

The system of equations:

Jack is 31 years old and Susan is 4 years old.