If 2 inches are equivalent to 5 centimeters, how many square centimeters are in one square inch

Can someone check if i did this correct. it’s number 4 if you’re wondering.

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.

According to the general equation for conditional probability if p(anb)=3/7 and p(b)=7/8 what is p(a i b)