Level 3
Cindy bought 6 pens and sharpeners altogether. The mass of each pen was 3 g. The mass of each sharpener was 5 g. The pencils and sharpeners weigned 21 g in total.
Level 3
Mr Lee is 45 kg heavier than his son, Jake and 24 kg heavier then his daughter, Emerald. Given that their total mass is 252 kg, how much does Mr Lee weigh?