Answer:
It will take 4 years
Step-by-step explanation:
The formula of the simple interest is <em>I = Prt</em>, where
- <em>P</em> is the investment
- <em>r</em> is the annual rate in decimal
∵ The investment is $40000
∴ <em>P</em> = 40000
∵ The simple interest is $8000
∴ <em>I </em>= 8000
∵ The rate of interest is 5%
∴ r = 5%
→ Change it to decimal by divide it by 100
∴ <em>r</em> = 5 ÷ 100 = 0.05
→ Substitute them in the formula above
∵ 8000 = 40000 × 0.05 × t
∴ 8000 = 2000t
→ Divide both sides by 2000
∴ 4 = t
∵ t is the time of investment
∴ It will take 4 years