Simple Interest and Percentages

20% of the students in Mr. Royal's classroom are 12 years old.  If there are 15 students in the classroom, how many students are 12 years old? 

• 2

• 3

• 4

• 5

What is the profit percent if a shopkeeper buys a football for $12 and sells it for $15?

• 80%

• 25%

• 20%

• 50%

A $900 laptop is discounted by 5%. What is the sale price of the laptop?

• $45

• $855

• $904.50

• $945

A 5% discount is applied to a mobile phone bill, which was $64.50. How much is the bill now?

• $62.80

• $60.82

• $59.50

• $61.28

Margaret sells mobile phones and receives 16.75% commission on her sales. If she sells a mobile phone worth $680, how much commission will she make?

• $113.90

• $100.50

• $16.75

• $117.25

The price of Fruit Tingles is now $1.50, they used to cost $1.25. What is the percentage price rise?

• 10%

• 20%

• 30%

• 40%

If a short term loan with principal $500 accrues $50 in interest and has to be paid back in 10 equal instalments. What will the amount of each instalment be?

• $45

• $50

• $55

• $50

A dinner set costing $250 is marked down (discounted) to $85. How much is the percentage discount? (2 decimal places)

• $165

• $85

• 63.46%

• 63.47%

If you are calculating the simple interest and you are given the time in months. How can you find the time in years?

• divide 12 by the months

• multiply 12 times the months

• divide the months by 12

• change the months to a decimal

How much is the interest?

• $26.25

• $46.45

• $25.00

• $55.50