Grade 7 - Math - Ratio Rate Speed

The length of the sides of a triangle are in the ratio 3 : 5 : 9.

Given that the length of the longest side is 102 cm more than the length of the shortest side, find the perimeter of this triangle.

The cash price of a camera is $1200. Kiara buys the camera on hire purchase. She pays a down payment of 20% of the cash price and the remainder by 24 monthly instalments at a simple interest rate of 2% per annum.

Find the amount of each monthly instalment.

A bank exchanged Japanese yen and Singapore dollars (S$) at a rate of 77 yen = S$1.

Calculate, in yen, the amount received for S$800.

A bank exchanged Japanese yen and Singapore dollars (S$) at a rate of 77 yen = S$1.

Calculate, in Singapore dollars, the amount received for 42 350 yen.

A bank offers an interest rate of 1.88% per annum for time deposits during Chinese New Year.

Sarah deposits $12 000 in the bank.

She plans to withdraw the interest at the end of each year.

How long would she need to deposit the money in the bank if she wants to earn $1128 of interest?

Caroline deposits $8000 in a bank for 2 years. The interest rate is 1.5% per annum. Find the total interest she will earn if she withdraws the interest at the end of each year.

Samuel is at the supermarket. He sees two different promotions for hand sanitizer. Which option gives the better value of money?

• Option A

• Option B

Jason travelled from town A to town B at a constant speed of 80 km/h for 1 hour 45 minutes. He rested at town B before travelling at a constant speed of 100 km/h for 2 hours to reach town C

Calculate the total distance he traveled

Jason travelled from town A to town B at a constant speed of 80 km/h for 1 hour 45 minutes. He rested at town B before travelling at a constant speed of 100 km/h for 2 hours to reach town C

If his average speed for the whole journey was 85 km/h, how long did he rest at town B?

State your answer in minutes.