If there are 91 slips of paper with odd or even numbers on them, and the probability of picking a slip with an odd number is 2/7, how many slips of paper have numbers divisible by 2 on them?

Question

myininaya · Answer

i would do
$$x+y=91, \frac{x}{x+y}=\frac{2}{7}$$

anonymous · Answer

Well, if the probability of picking an odd number is 2/7, then the probability of picking an even numbers is:
$$1-\frac{2}{7} = \frac{5}{7}$$
Then to figure out how many of those 91 papers are even we multiply:
$$91*\frac{5}{7}$$
 = 65? (someone check my math)

anonymous · Answer

Or myininaya's way, either or :P

anonymous · Answer

your math is correct

myininaya · Answer

26 odd
91-26 even

myininaya · Answer

gj joe

anonymous · Answer

thank you :) gj to you as well!