Åk 6–9

3.5 Exercises – Calculating with Percent
1. Calculate 10 % of:
 a) 78 kilo b) 8.8 c) 5.02 d) 547 liter e) 60 people f) 7.71 kr 2. Calculate:
 a) 75 % of 160 b) 45 % of 10 c) 70 % of 40 d) 25 % of 180 e) 90 % of 130 f) 95 % of 140 3. A delivery of fruit arrives at a store.  It contains 24 kg of pears and 26 kg of apples.  How many percent of the fruit are apples?  Write an expression for the proportion of apples and calculate it. 4. A store ordered 3.8 tons of apples and 6.2 tons of pears.  How many percent of all the fruit were apples? Write an expression for the proportion of apples and calculate it. 5. In a class with 30 students, 12 are girls.  How many in percent of the class is boys? Write an expression for the proportion of boys and calculate it. 6. Fill in the number so that the equalities apply.  Round your answer to tenths:
 a) 75 % of = 150 b) 45 % of = 144 c) % of 190 = 104.5 d) % of 50 = 5 e) 70 % of 100 = f) 20 % of 180 = 7. 80 % of a number is 144. What is the number?
Write and expression and calculate the number. 8. When I walk along a flat street, I have a speed of 5 km/h.  When I walk uphill, I have a speed of 3 km/h.  How many percent does my speed decrease when walking uphill? Write a mathematical expression and calculate the difference.