Money Birute deposited in a savings account = $500
Rate of simple interest per annum = 1.3%
▪︎We need to find the interest she will earn in 4 years.
We know that :
![\tt \: \color{hotpink}simple \: interest \color{plum}= \frac{principal \times rate \times time}{100}](https://tex.z-dn.net/?f=%5Ctt%20%5C%3A%20%5Ccolor%7Bhotpink%7Dsimple%20%5C%3A%20interest%20%5Ccolor%7Bplum%7D%3D%20%20%5Cfrac%7Bprincipal%20%5Ctimes%20rate%20%5Ctimes%20time%7D%7B100%7D%20)
In this case :
Principal = $500
Rate = 1.3%
Time = 4 years
Which means :
The simple interest she will earn in 4 years :
![= \tt \frac{500 \times 1.3 \times 4}{100}](https://tex.z-dn.net/?f=%20%3D%20%5Ctt%20%5Cfrac%7B500%20%5Ctimes%201.3%20%5Ctimes%204%7D%7B100%7D%20)
![= \tt \frac{2600}{100}](https://tex.z-dn.net/?f=%20%3D%20%5Ctt%20%5Cfrac%7B2600%7D%7B100%7D%20)
![\color{plum} = \tt\bold{\$26}](https://tex.z-dn.net/?f=%5Ccolor%7Bplum%7D%20%3D%20%5Ctt%5Cbold%7B%5C%2426%7D)
Thus, the simple interest she will earn in 4 years = $26
Amount = Principal + Interest
Amount she will gain after 4 years :
![=\tt 500 + 26](https://tex.z-dn.net/?f=%20%3D%5Ctt%20500%20%2B%2026)
![\color{plum} = \tt\bold{\$526}](https://tex.z-dn.net/?f=%5Ccolor%7Bplum%7D%20%3D%20%5Ctt%5Cbold%7B%5C%24526%7D)
Thus, the amount she will gain after 4 years = $526
Amount change in her account = 526 - 500 = 26
We know that :
![\tt \: \color{hotpink}percentage \: of \: change\color{plum} = \frac{change}{original \: price} \times 100](https://tex.z-dn.net/?f=%5Ctt%20%5C%3A%20%5Ccolor%7Bhotpink%7Dpercentage%20%5C%3A%20of%20%5C%3A%20%20change%5Ccolor%7Bplum%7D%20%3D%20%20%5Cfrac%7Bchange%7D%7Boriginal%20%5C%3A%20price%7D%20%20%5Ctimes%20100)
Which means :
Percentage of change in her savings account :
![=\tt \frac{26}{500} \times 100](https://tex.z-dn.net/?f=%20%3D%5Ctt%20%20%5Cfrac%7B26%7D%7B500%7D%20%5Ctimes%20100%20)
![=\tt \frac{26 \times 100}{500}](https://tex.z-dn.net/?f=%20%3D%5Ctt%20%20%5Cfrac%7B26%20%5Ctimes%20100%7D%7B500%7D%20)
![= \tt\frac{2600}{500}](https://tex.z-dn.net/?f=%20%3D%20%20%5Ctt%5Cfrac%7B2600%7D%7B500%7D%20)
![\color{plum} = \bold{\tt\bold{5.2\%}}](https://tex.z-dn.net/?f=%5Ccolor%7Bplum%7D%20%3D%20%5Cbold%7B%5Ctt%5Cbold%7B5.2%5C%25%7D%7D)
<h2>○=> Therefore :</h2>
▪︎Simple interest after 4 years = $26
▪︎Money she will earn after 4 years = $526
▪︎Percentage of change in her savings account = 5.2%