In a survey of eighth graders, 4 /5 of the students preferred using pens over pencils. what percent of the students preferred using pens?

Anne is twice as old as bill, and bill is 3 years older than christie. the sum of anne s and christie s ages equal 72. find their age difference.?

In need of in the diagram, ∠abc is a right angle. ∠dbc = 30°27'40". find the measure of ∠abd.

The ph level of a blueberry is 3.1 what is the hydrogen-ion concentration [h+] for the blueberry