te: 11/05/2020
Time: due to 8h00
Assignment of Mathematics of year 10 class
1. Natasha invests £250 in a building society account. At the end of the year her account is credited with 2% interest. How much interest had her £250 earned in the year?

2. Alan invests £140 in an account that pays r% interest. After the first year he receives £4.20 interest. What is the value of r, the rate of interest?

3. What is the actual rate of interest if £4000 deposited for 3 years attracts interest of £1440?

4. I deposit £250 in a high-earning account paying 9% compound interest and leave it for three years. What will be the balance on the account at the end of that time?

5. You borrow £500 for four years and agree to pay 6 1 2 % compound interest for this period. What amount will you have to pay back?

Question

contestada

Respuesta :

devishri1977 devishri1977 · Answer 1 · 2020-05-11T14:17:14+02:00

Answer:

Step-by-step explanation:

1) P = £ 250

r =2%

t = 1

I = Prt

[tex]=250*\frac{2}{100}*1\\[/tex]

Interest = £ 5

2) P = £140

I = £ 4.20

t = 1

[tex]4.20=140*\frac{r}{100}*1\\\\\frac{4.20*100}{140}=r\\\\r = 3[/tex]

r =3 %

3) P = £ 4000

t = 3 years

I = £ 1440

[tex]1440=4000*\frac{r}{100}*3\\\\1440*\frac{100}{4000*3}=r\\\\r=12[/tex]

r = 12%

4) Amount=p*[1+(r/100)]^t

[tex]=250*(1+\frac{9}{100})^{3}\\\\=250*(\frac{109}{100})^{3}\\\\=250*(1.09)^{3}\\\\[/tex]

= £323.76