Solve for z

HELP PLEASE

Mary had at least an 80% on her test write an inequality to represent this situation

Which situation can be modeled by the inequality 5 + 10w ≥ 45? a. you start with $5 and save $10 a week until you have at least $45. b.you start with 5 baseball cards and purchase 10 cards every week until you have at most 45 cards. c.you start with 5 water bottles and purchases cases of 10 water bottles each until you have a total of 45 water bottles. d.you spend $5 plus $10 per week until you have less than $45.

If a 36 inch yardstick casts a 21 foot shadow, how tall is a building whose shadow is 168 feet? what is the scale factor