What is the measure of

If there are 12 moths and some have 31 days and others have 30 days how many have 28 days?

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

Last month, a 770 g box of cereal was sold at a grocery store for $3.10. however, this month, the cereal manufacturer launched the same cereal in a 640 g box, which is being sold at $2.50. what is the percent change in the unit price?