3200 dollars is placed in an account with an annual interest rate of 8.25%. To the nearest tenth of a year, how long will it take for the account value to reach 9600 dollars?

24.2 years

Step-by-step explanation:

The basic formula is I = P * i * t, where I is interest, P is total principal (or profit), i is rate of interest per year, and t is total time in years. I = P * i * t can be rearranged to solve for t: t = I / (i * p).

In this question I = $6400, P = $3200 and i = 8.25%, so we plug in those numbers to get t = 6400 / (0.0825 * 3200), which solves to 24.2424 years.

answer: c, the green line

step-by-step explanation:

there is no black line, eliminate b.

simple interest implies periodic payments, but the red line shows no payments, eliminate d.

simple interest has equal payments. if paid say every day, the graph is about a straight line (actually a stairstep).

the yellow line is not straight, eliminate a.

check: the green line is straight, answer is c.

simple interest with positive interest rate gives a straight line sloping up to the right. green line:

g(t) = $100 + ($200-$100) ÷ (20 years) × (t years)

= $100 + (4%/year) × ($100)(t years)

incidentally, the yellow line curving upward represents continuously compounded interest

y = $100 × 2^(t years / (14 assuming the yellow line hits $200 at 14 years. 2^0 is 1, so y(0) = $100; 2^(14/14) is 2, so y(14) = $200.