Problem Solving

3.3 Problem Solving
SAVINGS & INVESTMENT
SAVINGS INVESTMENT
Money or valuables saved and used when in need. Money used for specific business which will give profits in the future.

 

EXAMPLE 1

 

Kevin saves \(\text{RM }1\ 000\) 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:

\(\text{RM }1\ \space000\times0.5\%=\\ \text{RM }1\ 000\times\dfrac{0.5}{1\cancel{00}}=\text{RM }5 \)

The total amount of money including the interest:

\(\text{ RM }1\space000+\text{RM }5=\text{RM }1\space005 \)

EXAMPLE 2

 

Encik Raihan received a cheque of \(\text{RM }2\ 500\) 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:

PERCENTAGE IN DAILY SITUATIONS
EXAMPLE 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:
\(\begin{aligned}\ \dfrac{85}{100}\times60=51\end{aligned}\\\)

The number of questions answered correctly:
\(60-51=9\)

EXAMPLE 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:
\(\space\space\space\space25.6\text{ million}+4\%\times25.6\ \text{ million}\\=25.6\text{ million}+\dfrac{4}{100}\times25.6\text{ million}\\ =25.6\text{ million}+1.024\text{ million}\\ =26.624\text{ million}\)

The increase in the number of tourists in 2016:
\(30\ \text{million}-26.624\text{ million}=3.376\text{ million}\)

The increase in percentage:
\(\dfrac{3.376}{26.624}\times100\%=12.68\%\)