Answer:
You should invest $2000 at 5% simple interest in order to earn $100 interest in 12 months.
Step-by-step explanation:
Using the formula

where
I = Interest earned
P = The principal (let say in $)
r = The Interest Rate
t = time
Given that
- P = The principal amount needed to invest (let say in $)
Thus,

100 = P × 5% × 1
100 = P × 5/100 × 1
100 × 100 = P × 5
10000 = P × 5
P = 10000/5
= 2000 (let say in $)
Thus, you should invest $2000 at 5% simple interest in order to earn $100 interest in 12 months.
Answer:
Total cost= $86.25
Step-by-step explanation:
Giving the following information:
Discount= 10%
Nill= $82.5
Tip= 15%
<u>First, we need to calculate the discounted price:</u>
Discount price= 82.5 / 1.1= $75
<u>Now, the tip:</u>
Tip= 75*0.15= $11.25
<u>Finally, the total cost:</u>
Total cost= 75 + 11.25
Total cost= $86.25