1. During World War II, when the Japanese
invaded Singapore, the price of the basic necessities increased drastically. Look at the
following prices of the object before and during the invasion of the Japanese. Calculate
the percentage increase in the price of the objects.
a) Soap --- 30 cents; $25
b) 500 g of rice --- $1.50; $75
c) Ball-Point Pen --- $2; $150
d) 1 kg of potatoes --- $6; $95
2. Mrs. Tay brought a refrigerator from the
salesman, Mr. Ho, at $870.
(a) What is the cost price of the refrigerator if it is sold
at a profit of 20%?
(b) What is the commission earned by Mr. Ho if for every
refrigerator sold, there is a 2% commission?
(c) Mrs. Tay decided to switch to the hire purchase scheme
and she will have to pay a deposit of $86 first. Then, over 8 months, she will have to pay
the monthly instalments and the 3% interest charged on the monthly instalments.
(i) How much does Mrs. Tay has to pay
each month?
(ii) If a 5% discount will be given when Mrs.
Tay pay all at once, how much will Mrs. Tay save if she pay all at once instead of
switching to the hire purchase scheme.
3. The 3 brothers, Bill, Ben and Buck
invested S$960 000, S$1 080
000 and S$1 320 000 respectively in building a company. They share the profit earned per
month in the ratio of their investment. 60% of the profit is saved for the company's
savings and development. The profit for that month was S$2 100 000.
(a) Calculate how much Ben received.
(b) How much more did Buck receive more that Bill?
(c) Buck used up 30% of his money and saved 50% of the
remaining money in a bank that gives 5% simple interest per annum. Then, he exchanged all
the remaining money to US$.
(i) How much did Bill receive after
leaving that amount of money into the bank for 2 years? (Assume that he did not withdraw
or deposit any money.)
(ii) How much US$ will he have now? (US$ 1 =
S$1.65)
