Question

Subtract $0.2J$ from $7.26J$ and express the result with correct number of significant figures.

• A. 7.1 J
• B. 7.06 J
• C. 7.0 J
• D. 7 J

Answer 1

The correct option is A 7.1 J

We know,

In addition or subtraction, the final result should retain as many decimal places as are there in the number with the least decimal places.

Arithmetic subtraction = 7.26 J - 0.2 J = $=7.06J$

But least precise measurement $0.2J,$ is correct to only one decimal place. So final result $=7.1J$