1/ The average height of 2 boys is 131.6cm . The average height of 4 girls is 128.3cm . What is the average height of all children ?
Answer : ....... cm
2/ Two years ago . Miss Lan's salary was $2300 . She got a 5% increment last year and a 10% increment this year . What is Miss Lan's salary now ?
Answer : $ ...... ?
3/ A rectanglar tank is 50cm long , 40cm wide and 45cm high . The height of the water level in the container is 15cm . How many more litres of water are roquired to fill up the tank compietely ?
Answer : ............. l