- A box containing 18 apples weighs 3 kg. Jane puts in 7 apples and 2 mangoes into the box and the total mass of the box with its contents becomes 4.92 kg. Each mango weighs 4 times as much as an apple.
(a) Find the mass of the box.
(b) What is the least number of apples that must be removed from the box so that the mass of the items in the box will not be more than 4.2 kg?