Line a is perpendicular to line b if the slope of line a is -4 what is the slope of line b?

Ihonestly don’t understand this at all

An appliance salesman sets a goal to sell an average of 6 appliances per day for the first two weeks of his new job. the dot plot shows the number he sold each day during the first 13 days. what is the minimum number of appliances he must sell on the 14th day in order to reach his goal? a) 5 b) 6 c) 7 d) 8

Diana is painting statues she has 7/8 of a liter of paint each statue requires 1/20 of a liter of paint how many statues can she paint?