Which lines are perpendicular?

The price of an item has been reduced by 30%. the original price was $30. what is the price of the item now ?

If olu is twice as old as funmi if the sum of their ages is 60 how old is olu

Asmall business produces and sells balls. the fixed costs are $20 and each ball costs $4.32 to produce. each ball sells for $8.32. write the equations for the total cost, c, and the revenue, r, then use the graphing method to determine how many balls must be sold to break even.