Question

Which answer, to the correct number of significant figures, is closest to the true value of the expression: (9.1 x 104 )(1.1 x 10-5 )(log 10-13)(1000)g

Answer 1

Answer : The correct answer is, -13000 g

Explanation :

Significant figures : The figures in a number which express the value -the magnitude of a quantity to a specific degree of accuracy is known as significant digits.

The rule apply for the multiplication and division is :

The least number of significant figures in any number of the problem determines the number of significant figures in the answer.

The given expression is:

`(9.1* 10^4)(1.1* 10^(-5))(\log 10^(-13))(1000)g`

As we know that,

`\log 10^(-13)=-13`

`\Rightarrow (9.1* 10^4)(1.1* 10^(-5))(-13)(1000)g`

`\Rightarrow -13013g`

True value means, the rounding off the number. So,

`\Rightarrow -13000g`

Therefore, the correct answer is, -13000 g