Answer: Choice B) 3 years
--------------------------------------
Step-by-step explanation:
The simple interest formula is
i = P*r*t
where,
i = interest
P = principal
r = interest rate in decimal form
t = time in years
In this case,
i = 840
P = 7000
r = 0.04 (move the decimal point 2 spots to the left go to from 4% to 0.04)
t = unknown; we'll leave it as t
Plug the given values above and solve for, or isolate, t
i = P*r*t
840 = 7000*0.04*t
840 = 280*t
840/280 = 280*t/280
3 = t
t = 3
It will take 3 years