If my mother's current age is twice of my age+12 after 8months my mother age will be thrice of my age 20 then find out what is the current age of my mother?

Fatima plans to spend at least $15 and at most $20 dollars on sketch pads and pencils. if she buys 2 sketchpads, how many pemcils can she buy while staying in her price range? fatima can buy between and pencils. ? (type whole numbers. use ascending? order.)