Can someone help me understand how you get these answers?

Siri can type 90 words in 40 minutes about how many words would you expect her to type in 10 minutes at this rate

The candy store is having a 30% off sale. emma is going to buy $7.50 worth of candy. how much will she pay after the discount

He letter p on the number line below represents the number . (use the hyphen for negative numbers and write answer as a decimal, such as –7.2) number line from negative 7 to positive 7 in increments of 0.5 is shown. only the whole numbers are labeled. a point labeled p is placed at the eleventh tick mark to the left of 0.