The mass of a box measured by a grocer's balance is 2.3 kg. Two gold pieces of masses 20.15 g and 20.17g are added to the box. What is (a) total mass of the box (b) the difference in masses of gold pieces to correct significant figures.

Options

A. 2.3 kg
B. 2.34 kg
C. 2.340 kg
D. 2.3403 kg

Answer

A

Explanation

Here, mass of the box, `m=2.3kg`
Mass of one gold piece, `m_(1)=20.15g=0.02015kg` ltBrgt Mass of the other gold piece, `m_(2)=20.17g=0.02017kg`
`therefore` Total mass `=m+m_(1)+m_(2)` ltb rgt `=2.3kg+0.02015kg+0.02017kg=2.34032kg`
As the result is correct only upto one place of decimal, therefore, on rounding off, we get
Total mass=2.3 kg