Question

In math class, Sam correctly multiplied 3.625×10-8 by 500, then reported his product in scientific notation.

Answer 1

Question:

In math class, Sam correctly multiplied 3.625×10-8 by 500, then reported his product in scientific notation. What was the exponent in Sam’s product? A -16 B -10 C -7 D -5

Answer:

OPTION D

The exponent in Sam’s product is -5

Solution:

Given that,

In math class, Sam correctly multiplied $3.625 \times 10^{-8}$ by 500, then reported his product in scientific notation.

To find: exponent in Sam’s product

Let us first multiply 500 with $3.625 \times 10^{-8}$

$3.625 \times 10^{-8} \times 500 = 1812.5 \times 10^{-8}$

Then Sam has reported this answer in scientific notation

Lets understand what is scientific notation of any number.

Scientific notation is a way of representing number between 1 and 10 incluing 1 and excluding 10 multiplied by appropriate power of 10.

Let us rewrite the Sam's answer in scientific notation

The format for writing a number in scientific notation is:

(first digit of the number) followed by (the decimal point) and then (all the rest of the digits of the number), times (10 to an appropriate power).

In $1812.5 \times 10^{-8}$ , we move the decimal 3 times to left side

Since the decimal is moved left side, we multiply by $10^3$

$1812.5 \times 10^{-8} = 1.8125 \times 10^3 \times 10^{-8} \\\\1812.5 \times 10^{-8} = 1.8125 \times 10^{-5}$

Exponent is a quantity representing the power to which a given number or expression is to be raised

So in $1.8125 \times 10^{-5}$ exponent is -5