Question

How many significant figures will be there in the calculated solution of following problem: $\frac{(29.2-20.2)\times (1.97\times {10}^5)}{1.39}$?

• A. 3
• B. 1
• C. 4
• D. 2

Answer 1

Answer: (D)

2

The result of addition and subtraction cannot have more digits to the right of the decimal point than either of the original numbers.

In case of division and multiplication, the result must be reported with no more significant figures as are there in the measurement with the few significant figures.

Therefore, $29.2-20.2=9.0$.

Thus, the answer to this subtraction will be upto one decimal place.

Now, $\frac{(29.2-20.2)\times (1.97\times {10}^5)}{1.39}=\frac{\left(9.0\right)\times (1.97\times {10}^5)}{1.39}$.

Thus, the answer to this term will be upto 2 significant figures.

Hence, option D is correct.