Imogen bought i number of invitations to send out for her party. after she sent out 19, she was left with 11. what is the value of i?

Can (2,3 and square root 10) be sides ona right triangle?

When you are making a circle graph by hand, how do you convert a number for a part into its corresponding angle measure in the circle graph? when you are making a circle graph by hand, what should you do if one of your angle measures is greater than 180°?

Prove that 16^4-2^13-4^5 is divisible by 11.