1. Every year the value of an operating machine depreciates by 18% of its value in the previous year.
If
the value of the machine was $39 335.40 in 2012, find its value in 2010.
2. A smartphone which costs $ 740, excluding 7% goods and services tax, is sold at a loss of 7% on the
cost price. Find its selling price.
2 1 1
3. (a) Find the value of a if 9
:� = 4
:23
5
(b) Simplify 600�� : 1 8 � : 2.75 �.
4. A certain amount of money is shared among Ahmad, Benny and Mike. The ratio of Ahmad’s share to
Benny’s share 3:4 and that of Benny’s share to Mike’s share is 5:6. If Ahmad and Mike receive $ 663
altogether, find the sum of money that is shared among the three boys.
5. The exchange rate between the sterling pound (£) and the Swiss France (₣) on a particular day is
£1=₣ 1.4425.
Find (i) the number of complete Swiss francs that can be exchanged for £825,
(ii) the number of complete sterling pounds that can be exchanged for ₣1600.
6. A car travels the first 20 km of its journey in 24 minutes, the next 40 km at an average speed of 60
1
km/h and the remaining 27 2 �� at an average speed of 66 km/h. Find the average speed of the car
for its entire journey.
5�−6�+�
7. Given that x is 120% of y and y : z = 13 : 11, find the value of 2�−�
.
8. The ratio of Jeanette’s age to Laura’s age now is 5 : 3. In 7 years’ time, their ages will be in the ratio
11 : 8. Find the Jeanette’s age in 7 years’ time.
9. 120 cm3 of a solution contains water and vinegar in the ratio 5 : 1. Find the amount of vinegar that
has to be added so that the ratio of the amount of water to that of vinegar in the solution becomes 4:1.
10. If the value of a is increased by 20% and the value of b is decreased by 15%, find the percentage
change in the value of the square of the product of a and b.
