Question

Alex invests £4000 for 7 years.

His investment pays compound interest of x% per annum.
At the end of the 7 years Alex’s investment is worth £5263.73
Work out the value of x

Answer 1

x=4%

that will get you all the marks lol

Answer 2

Answer: x=4% i.e.

Rate of interest = 4% per annum.

Explanation:

Since we have given that

Amount Alex invested = £4000

Number of years = 7

Rate of interest = x%

Amount she received at the end of 7 years = £5263.73

We will use " Compound Interest " formula :

`A=P(1+(r)/(100))^n\\\\5263.73=4000(1+(x)/(100))^7\\\\(5263.73)/(4000)=(1+(r)/(100))^7\\\\(526373)/(400000)=(1+(r)/(100))^7\\\\1.3159325=(1+(r)/(100))^7\\\\(1.3159325)^{(1)/(7)}=1+(r)/(100)\\\\1.04=1+(r)/(100)\\\\1.04-1=(r)/(100)\\\\0.04=(r)/(100)\\\\4=r`

Hence, x=4% i.e.

Rate of interest = 4% per annum.