What is the sum of the first five terms of a geometric series with a 1=20 and r=1/4 !

Jenisey has $24 to spend on seven pencils. after buying them she had $10. how much did each pencil cost.?

Atheater wants to build movable steps that they can use to go on and off the stage. they want the steps to have enough space inside so they can also be used to store props. how much space is inside the steps?

The standard deviation for a set of data is 5.5. the mean is 265. what is the margin of error?