Percent, Discount, Commission and Simple Interest

A piece of string 420 cm long is divided into the ratio of 3:2. Find the lengths of the 2 parts.

• 300cm and 120 cm

• 240cm a nd 180 cm

• 252 cm and 168 cm

• 256 cm and 164 cm

The ratio of boys to girls in a class is 4: 3. If there are 15 girls, how many boys are there in the class?

• 20 boys

• 24 boys

• 20 girls

• 24 girls

Which of the following is not a unit for speed?

• kilometer/hour

• meter/minute

• kilowatt/hour

• miles/second

A map is drawn on a scale of 1cm to 6m. What is the length of a line on the map which represents the distance of 72 m?

• 15 cm

• 12 cm

• 15 m

• 12 m

A car requires 15 L of petrol to travel 200 km. How much petrol is needed to travel 120 km?

• 90 L

• 9 L

• 18 L

• 12 L

What is 20% of 900?

• 1800

• 108

• 18

• 180

Which of the following expression equals 25%

• 25/1000

• 1/5

• 0.025

• 1/4

Express 28 as a percentage of 40.

• 70%

• 60%

• 50%

• 40%

Express 5 kg as a percentage of 500 grams.

• 10%

• 100%

• 1000%

• 1%

A vendor bought a shirt for180 baht and sell it for 220 baht.

What percent was the profit of the cost price?

• 22%

• 22.22%

• 12%

• 12.12%