Taking into account of the significant figures, what is the value of 9.99 m - 0.0099 m ?

(1) 9.9 m

(2) 9.9801 m

(3) 9.98 m

(4) 9.980 m

(1) 9.9 m

(2) 9.9801 m

(3) 9.98 m

(4) 9.980 m

**Answer - **(3) 9.98m

**Solution - **9.99 - 0.0099 = 9.9801

While performing addition or subtraction we have to assign the no.of significant figures in the answer based on the least no.of decimal digits in one of the measurement. Here 9.99 has the least no.of decimal digits, thus we should round off the answer to 2 decimal digits.

Thus, Answer = 9.98m