Level 3
The average height of a group of 6 girls is 137 cm. When Kathy and Nicole joined the group, the average height increased by 4 cm. What is Kathy and Nicole's total height?
Level 3
Five numbers were written on the whiteboard as shown:
Write down the 3 numbers that will give an average of 51.
After John wrote 2 -digit number on the same whiteboard, the new average of the six numbers became a multiple of 3. What was the largest possible 2-digit number written by John?
Level 3
Five numbers were written on the whiteboard as shown:
Write down the 3 numbers that will give an average of 51.
After John wrote 2 -digit number on the same whiteboard, the new average of the six numbers became a multiple of 3. What was the largest possible 2-digit number written by John?
Level 3
The average mass of a group of girls was 37 kg. When Jamie, a girl, joined the group, the average mass of the group became 34 kg. If Jamie had a mass of 22 kg, how many girls were there in the group in the end?
Level 3
The average height of some boys is 145 cm. When 3 girls, with a total height of 393 cm, are included, the average height if the children becomes 142 cm. How many children are there altogether?
Level 3
Simon has some black and red balls. The total mass of all his balls is 242 g. He has 5 more red balls than black balls. The average mass of the black balls is 6 g. The average mass of the red balls is 10 g. How many balls does Simon have altogether?
