1. Mr. Chen started to drive from Town A to Town C at 0900. He reached Town B at 1400 and had an hour rest there. He then drove on to Town C where he increased his speed to 110 km/h. Given that the total distance between Town A and Town C is 780 km and the ratio of the distance between Town A and B and the distance between Town B and C is 15 : 11, find the following:                                                                                  (a) At what speed is Mr. Chen is driving when he is driving from Town A to        B?  (2)                                                                                             (b) At what time did he reach Town C? (2)                                               (c) What is the average speed for the whole journey? (1)                          (d) At what speed must he travel in order to reach Town C by 2 hours         later?  Calculate the percentage decrease in speed compared to the        original speed when travelling from Town B to C. (2)                                      
2. (a) It takes 30 men to fix 2 aeroplanes in 4 hours. How many more men           is needed when 3 aeroplanes needs to be be fixed within 5 hours?           (Assume that they have the same speed of fixing the aeroplanes.) (2)

    (b) If 5 men need 10 days to paint a house, how many men are required            to paint 7 houses in 5 days? (Assume that they have the same skill            and speed in painting.)  (2) 

3. James deposited $15 000 in Bank A and $5000 in Bank B. 2 years       later, he received 1.8 times more interest in Bank A than in Bank B. Find the relationship between the interest rate per annum given by Bank A and B. Given that the interest rate of Bank B is 5%, find the total amount of money James have in both bank after 2 years.  (3)

4. Jack is a salesman. He works 5 days a week and has a basic salary of $480 per month. He draws a commission of 25% on all goods sold.             (a) Calculate the daily rate of his basic salary.  (1 month = 4 weeks)  (1)     (b) Calculate the value of the goods he sold if he made $1150 that month.        (2)         

Jack's performance was very good and his basic salary was rised to $620 a month.                                                                                                 (c) Calculate the daily rate of the new basic salary. (1 month = 4 weeks) (1)   (d) Calculate the percentage increase of the daily rate of the new basic salary. (2)                                                                                             (e) Calculate the total amount of money he made if the value of the goods sold is $2272. (2)

5. A computer is sold at $2584. The computer company also offers a hire purchase system which allows the buyer to pay a downpayment of $1000 and $184.80 per month for 9 months.                                                       (a) Find the price difference between paying all at once and buying the computer through the hire purchase system.  (1)                                       (b) Calculate the interest rate charged on the monthly instalments. (2)

6. It took 7 men to make 18 chairs in 12 hours. How long does it take 9 men to make 42 chairs? (Round off to 2 decimal places.)  (2)

7. A container is filled with 56 litres of pineapple juice. 8 litres of pineapple juice are removed and the container is refilled with mango juice. The content of the container is thoroughly mixed and 8 litres of the mixture are then removed and the container is again refilled with mango juice. What is the ratio of the mango juice to pineapple juice in the final mixture? (3)                                                                               (Extracted from Sec. 1 Maths Textbook, Pg. 232, Challenge Yourself, Question 3)