Level 3
A tank is to be filled to the brim. Tap A takes 20 minutes to fill the tank while Tap B takes 15 minutes to fill it. How long will it take to completely fill the tank with water if both the taps are turned on at the same time? Leave the answer in minutes and round off to 1 decimal place.
4 m
Level 3
It takes Faucet X 15 minutes to fill a tank measuring 14 cm by 8 cm by 12 cm completely while it takes Faucet Y only 10 minutes. How long will it take to completely fill the tank with water if both faucets are turned on at the same time and 3 cubic cubes of edges 3 cm, filled with water, are poured into the tank? Leave the answer in minutes and round off to 2 decimal places.
4 m
Level 3
Study the patterns.
  1. Find the total number of triangles in Figure 30.
  2. Express the biggest triangle as a percentage of the total possible number of triangles in Figure 30. Correct your answer to 2 decimal places.
5 m
Level 3
Vincent has some 20-cent coins and 50-cent coins which amount to more than $20 but less than $54. The number of 20-cent coins is 14 of all the coins he has. When he exchanges some 50-cent coins for 20-cent coins, the ratio of the number of 50-cent coins to 20-cent coins he now has become 1 : 6.
  1. What is the largest possible amount of money Vincent has?
  2. What is the total value of 50-cent coins that has been exchanged for 20-cent coins? Express the answer to 2 decimal place.
5 m
Level 3
The figure is made up of a big semicircle of diameter 8 cm and 2 small semicircles with diameter 5.7 cm. Find the shaded area. Round off the answer to nearest 1 decimal place. (Take π = 3.14)
4 m