не знаю как решить задачи для поступления, помогите.

Пожалуйста, помогите решить эти задачи с кратким решением или обьяснением. У меня нет никого из математиков, а сама давно уже школу закончила и все забыла, но вот надо решить подобные задачи для поступления. Всем спасибо заранее.
1. If Lynn can type a page in p minutes, what piece of the page can she do in 5 minutes?
A. 5/p B. p - 5 C. p + 5 D. p/5 E. 1- p + 5
2. If Sally can paint a house in 4 hours, and John can paint the same house in 6 hour, how long will it take for both of them to paint the house together?
A. 2 hours and 24 minutes B. 3 hours and 12 minutes C. 3 hours and 44 minutes D. 4 hours and 10 minutes E. 4 hours and 33 minutes
3. Employees of a discount appliance store receive an additional 20% off of the lowest price on an item. If an employee purchases a dishwasher during a 15% off sale, how much will he pay if the dishwasher originally cost $450?
A. $280.90 B. $287 C. $292.50 D. $306 E. $333.89
4. The sales price of a car is $12,590, which is 20% off the original price. What is the original price?
A. $14,310.40 B. $14,990.90 C. $15,290.70 D. $15,737.50 E. $16,935.80
5. Solve the following equation for A : 2A/3 = 8 + 4A
A. -2.4 B. 2.4 C. 1.3 D. -1.3 E. 0