Renee knit a total of 39 centimeters of a scarf over 3 nights. How many nights will renee have to spend knitting in order to knit a total of 65 centimeters of the scarf

Empty box + box + empty box fill in the box is equal to 30 how

Jake bakes and sell apple pies. he sells each pie for $5.75 . the materials to make the pies cost $40. the boxes jake puts the pies in cost & 12.50 total. how many pies does jake need to sell to earn a profit of $50

Math i have no idea how to do a and b