A grocer's balance reads the mass of a box as 2.3 kg. If two gold pieces of masses 20.15 g and 20.17 g are added to the box, then what will be the total mass of the box?

Here, mass of the box, m = 2.3 kgMass of one gold piece,m1 = 20.15 g = 0.02015 kgMass of other gold piece,m2 = 20.17 g = 0.02017 kgTotal mass = m + m1 + m2. = 2.3 kg + 0.02015 kg + 0.02017 kg = 2.34032 kgAs the result is correct only up to one place of decimal, therefore, on rounding off, we getTotal mass = 2.3 kg