Suppose that Saleem has money in a savings account that pays him interest of 5% per year on the account balance. Now, Saleem takes out $50 a month, and his mother deposits $240 every 6 months into the account. Assuming that the interest is paid and money is deposited and withdrawn from the account in a continuous fashion, the balance B = B(t) (in dollars) remaining in the account at the time t (in months) is best modeled by the differential equation:

Question

Suppose that Saleem has money in a savings account that pays him interest of 5% per year on the account balance. Now, Saleem takes out $50 a month, and his mother deposits $240 every 6 months into the account. Assuming that the interest is paid and money is deposited and withdrawn from the account in a continuous fashion, the balance B = B(t) (in dollars) remaining in the account at the time t (in months) is best modeled by the differential equation:
A. dB/dt = (.05B/12) - 50
B. dB/dt = (.05B/12) - 190
C. dB/dt = .05B - 50
D. dB/dt = .05B - 120
***E. dB/dt = (.05B/12) - 10
*** I think it is E because interest is divided by number of months +$40 and -50.

Anonymous · Accepted Answer

I agree with you.