The mass of a box measured by a grocer's balance is 2.300kg. Two gold pieces of masses 20.15 g and 20.17 g are added to the box. What is (a) the total mass of the box, (b) the difference in the masses of the pieces to correct significant figures?

Explanation

(a) Total mass of box `=2.300+0.02015+0.02017`
`=2.34032kg= 2.3kg` (correct up to one decimal place)
(b) Difference in the masses of pieces
`=20.17-20.15=0.02g` (correct upto one decimal place).