Question

I need help. Can someone pls answer with working thx

Answer 1

Question 1:

The given formula is

`I=(PTR)/(100)`

To make T, the subject we multiply both sides by 100:

`100I=(PTR)/(100) * 100`

This becomes

`100I=PTR`

Divide both sides by PR

`T=(100I)/(PR)`

b) Amanda's principal is , P=€2565

The interest rate is 3.5% p.a. that is R=3.5

We want to find how many years, her money will gain an interest of I=€718.20

We substitute into the formula for T,

`T=(100 * 718.20)/(2565 * 3.5)`

This simplifies to:

T=8

Therefore it will take 8 years

2) Percentage profit

`= (profit)/(cost \: price) * 100\%`

The cost price of the 80 articles €200

The selling price is 3.5×80=€280

The profit =€280-€200=€80

The percentage profit is now

`= (80)/(200) * 100\%`

`= 0.4 * 100\%`

`40\%`

The percentage profit is 40%

Question 3)

Let the original price of the calculator be x.

Then 85% of this price will be:

`(85)/(100) * x`

This is the same as€32.89

We equate and solve for x.

`(85)/(100) x= 32.89`

`0.85x = 32.89`

`x = (32.89)/(0.85)`

`x = 38.69`

The original price is €38.69