11 MAT 1.4 Proportional Reasoning & Percentages Quiz

A recipe uses 2 cups of flour for 3 cups of milk. How many cups of milk are needed for 6 cups of flour?

Answer explanation

The ratio of flour to milk is 2:3. For 6 cups of flour, multiply the milk by 3 (6/2). Thus, 6 cups of flour require 9 cups of milk (3 * 3).

What is 35% of $120?

Answer explanation

To find 35% of $120, multiply 120 by 0.35. This gives you $42. Therefore, 35% of $120 is $42.

A shirt is discounted by 20%. Its original price was $80. What is the new price?

Answer explanation

To find the new price after a 20% discount on an $80 shirt, calculate 20% of $80, which is $16. Subtract this from the original price: $80 - $16 = $64. The new price is $64.

A bag of 5 apples costs $3.75. What is the cost per apple?

Answer explanation

To find the cost per apple, divide the total cost by the number of apples. $3.75 ÷ 5 = $0.75. Therefore, the cost per apple is $0.75.

If 3 pencils cost $1.50, how much would 10 pencils cost?

Answer explanation

If 3 pencils cost $1.50, then 1 pencil costs $0.50. Therefore, 10 pencils would cost 10 x $0.50 = $5.00.

A scale map shows 1 cm = 50 km. What distance is represented by 7.5 cm?

Answer explanation

To find the distance represented by 7.5 cm, multiply 7.5 by 50 km. Thus, 7.5 cm = 7.5 * 50 = 375 km. Therefore, the distance represented is 375 km.

You make 2 litres of juice using 1 part concentrate to 4 parts water. How much concentrate do you need?

Answer explanation

To make 2 litres of juice with a 1:4 ratio of concentrate to water, you need 1 part concentrate and 4 parts water, totaling 5 parts. Therefore, concentrate needed = 2 litres / 5 parts = 0.4 litres.

Which is better value: 900 g of rice for $3.60 or 1.2 kg of rice for $4.80? Show your reasoning.

Answer explanation

To compare values, calculate the price per gram. For 900 g at $3.60, it's $0.004 per gram. For 1.2 kg (1200 g) at $4.80, it's $0.004 per gram. Both are equal in value, but the 900 g option is cheaper overall.

A T-shirt marked '25% off the sale price' now costs $18. What was the original price?

Answer explanation

The T-shirt is 25% off the sale price, meaning you pay 75% of the sale price. If $18 is 75%, the original price is $18 / 0.75 = $24.

Explain why increasing a number by 20% then decreasing it by 20% doesn't return to the original.

Answer explanation

Increasing a number by 20% raises it to 1.2 times its original value. Decreasing this new value by 20% reduces it to 0.96 times the original, not returning to the original number. Thus, the final result is less than the starting value.