Question

Two-fifths of a liquid’s volume, v, evaporates from a container.

Which statement explains why both 2/5v and 0.4v can find the volume of the evaporated liquid?

A. The expressions are not equivalent.

B. Multiplying by 2/5 is the same as multiplying by 40%.

C. Multiplying by 2/5 is the same as multiplying by 4%.

D. The fraction 2/5 is the same as the decimal 0.6. Therefore, 2/5v can be written as 0.6v.

Answer 1

The parameter 2/5 is a fraction while the parameter 0.4 is a decimal. You can convert the decimal into fraction by dividing the digit to its place value. Since 4 is in the tenths place,

0.4 = 4/10
Simplifying,
4/10 = 2/5

Thus, 2/5 = 0.4. When you multiply 100 to the decimal form, that would be expressed in percentage. Thus, 0.4 = 40%. The answer is B.