## Percentages

 4.1 Solve the Problems

Percentage in savings and investments

• Savings is money or valuables saved and used when in need..
• Investment is money used for specific business such as buying shares and becoming a member of the school’s cooperative which will give profits in the future.

Situation 1

Kevin saves RM1 000 in a bank. The bank gives an interest rate of 0.5% for the savings. Calculate the interest for his savings and the total amount of money that he will have.

Solution:

The interest

$$RM1\ \space0\space0\space0\times0.5\%=\\ RM1\ \space0\cancel{\space0\space0}\times\dfrac{0.5}{1\cancel{\space0\space0}}=RM5$$

The total amount of money including the interest

$$RM1\space\space0\space0\space0+RM5=RM1\space\space0\space0\space5$$

Situasi 2

Encik Raihan received a cheque of RM2 500 as payment for his shop’s rental in January. He deposited it in his bank account and received an interest rate of 0.8% per month. Calculate the amount of money at the end of the month.

Solution:

\begin{aligned}\small{\color{red}4}\quad\quad\quad\quad\quad\quad\quad\quad\quad\quad\quad\quad\quad\\ \dfrac{RM\cancel{20}}{RM\cancel{2\ 500}}\times100\%=\dfrac{4}{5\cancel{00}}\times1\cancel{00}\%\\ \small{\color{red}{500}}\quad\quad\quad\quad\quad\quad\quad\quad\quad\quad\quad\quad\space\space\\ =0.8\%\quad\quad\quad\\ \end{aligned}\\

Percetage in daily situations

Situation 1

Vasanti obtained 85% in a test. There were 60 questions in the test. How many questions did Vasanti answer wrongly?

Solution:

The number of questions answered wrongly:

\begin{aligned}\small{\color{red}{17}}\quad\space\space\space\small{\color{red}3}\quad\space\quad\quad\\ \dfrac{\cancel{85}}{\cancel{10}\cancel0}\times\cancel6\cancel0=51\\ \small{\color{red}\cancel2}\quad\quad\quad\space\space\space\quad\quad\\ \small{\color{red}1}\quad\quad\quad\quad\space\space\space\quad\end{aligned}\\

The number of questions answered correctly:

$$60-51=9$$

Situation 2

In 2014, the number of tourists who visited Malaysia was 25.6 million. In 2015, the number of tourists increased by 4%. In 2016, there were 30 million tourists. What was the increase in percentage in 2016 compared to 2015?

Solution:

The number of tourists in 2015:

$$\space\space\space\space25.6\ million+4\%\times25.6\ million\\=25.6\ million+\dfrac{4}{100}\times25.6\ million\\ =25.6\ million+1.024\ million\\ =26.624\ million$$

The increase in the number of tourists in 2016:

$$\space\space\space\space30\ million-26.624\ million=3.376\ million\\$$

The increase in percentage:

$$\dfrac{3.376}{26.624}\times100\%=12.68\%$$