Level 1
Fill in the blanks.
The number of boys is 4 times as many as the number of girls.
The number of adults is twice the number of boys.
Let the number of girls be 1 u.
Level 3
Some stickers are packed into exactly packets of 10.
If the stickers are repacked into packets of 7,
there are 4 more packets and 2 stickers left.
Level 3
There are 3 boxes.
The total mass of Box A and Box B is 160 kg.
The total mass of Box B and Box C is 200 kg.
The total mass of Box C and Box A is 180 kg.
Find the total mass of Box A, Box B and Box C.