Sec 3 E-Math Percentage & Personal Finance topical questions

Express 63 as a percentage of 280.

A crowd of 2 400 grows to 3 000. Find the percentage increase.

A bag of rice weighing 5 kg is sold with 8% extra free. Find the total weight of the bag.

After a 4% pay rise, Dev earns $2 912 per month. Find his original monthly salary.

Find the simple interest on $650 at 4% per year for 3 years.

A jacket is sold at an 18% discount for $98.40. Find the original price.

Express 9 minutes as a percentage of 2 hours.

A gym charges $88 per month. (a) Membership rises 5% in January and a further 5% in July. Find the monthly fee after July, correct to the nearest cent. (b) State the overall percentage increase for the year.

1. (a)Find the July fee.[4]
2. (b)State the overall percentage increase.[2]

A laptop is advertised at $1 680 before GST, which is charged at 9%. (a) Find the GST-inclusive price. (b) The shop offers a 10% discount on the GST-inclusive price for cash. Find the cash price, correct to the nearest cent.

1. (a)Find the GST-inclusive price.[2]
2. (b)Find the cash price.[3]

Mr Tan’s chargeable income is $46 000. Tax rates: 0% on the first $20 000, 2% on the next $10 000, 3.5% on the next $10 000, 7% on the remainder. Compute his tax.

Find the compound interest on $2 500 for 2 years at 8% per year, correct to the nearest cent.

A refrigerator costs $1 240 cash. On hire purchase: a 25% deposit, then the balance plus 6% p.a. simple interest for 18 months, repaid in 18 equal monthly instalments. (a) Find the deposit. (b) Find each monthly instalment, correct to the nearest cent.

1. (a)Find the deposit.[2]
2. (b)Find each monthly instalment.[5]

One unit of a foreign currency costs $0.78. (a) How many units can be bought for $936? (b) The exchange desk takes a 1.5% commission on the dollar amount before converting. With commission, how many units does the customer receive?

1. (a)Units bought for $936 without commission.[2]
2. (b)Units received after the 1.5% commission.[3]

Find the difference between the compound interest and the simple interest on $6 000 at 5% per year for 2 years.

A shopkeeper marks a jacket 60% above the price he paid, then sells it at a 25% discount off the marked price. The selling price is $207. (a) Find the price he paid. (b) Express his profit as a percentage of the price he paid.

1. (a)Find the price he paid.[4]
2. (b)Find the profit percentage.[3]

Two shops sell the same model of bicycle. Shop A prices it at $900 less 15%, then a further 10% off the reduced price for members. Shop B prices it at $850 less 22% for everyone. (a) Find each shop’s member price. (b) Which shop is cheaper for a member, and by how much?

1. (a)Find both member prices.[4]
2. (b)State which shop is cheaper and by how much.[2]

An investor puts $12 000 into a fund that pays 4% per year compound interest, compounded yearly. (a) Find the value of the investment after 3 years, correct to the nearest cent. (b) A second fund offers 4% per year compounded half-yearly. Explain, without full calculation, which fund leaves more after 3 years, and find the difference to the nearest cent.

1. (a)Value after 3 years, compounded yearly.[4]
2. (b)Compare with half-yearly compounding and find the difference.[4]

A family’s monthly utilities bill is computed with tiered rates: the first 250 kWh cost $0.2544 per kWh and every further kWh costs $0.3253, before 9% GST. Last month the family paid a GST-inclusive total of $118.77. Find the number of kWh used, correct to the nearest whole number.

A gaming laptop’s price was reduced by 20% in a sale. After the sale ended the shop raised the sale price by 20%. The final price is $1 152. Find (a) the original price and (b) the overall percentage change from the original price to the final price.

A car bought for $95 000 loses 8% of its value each year. (a) Find its value after 3 years, correct to the nearest dollar. (b) Find the total percentage loss over the 3 years, correct to 3 significant figures.

1. (a)Value after 3 years.[3]
2. (b)Total percentage loss (3 s.f.).[3]