Julia preheated her oven for 18 minutes. What fraction of an hour was this?  

The price of a printer was reduced from $400 to $160. What was the percent of decrease?

Solve for in the proportion:  

5. Eukaryotic chromosomes are composed of a complex of 60% protein and 40% DNA. This complex is referred to as:  

Write a fraction to represent the shaded portion of the figure.

29. During this stage of mitosis, the chromosomes become attached to the spindle at their kinetochores.  

If the ratio of boys to girls in a class is 1:6, what is the ratio of girls to all students in the class?

47. The point of connection between two sister chromatids, before anaphase II of meiosis separates them, is called the  

Write the number 0.000265 in scientific notation.

If a and b are rational numbers with and , and if m is an integer, determine if the following is true or false: