One mango weighs the same as 4 kiwi fruit and 2 pears. One pineapple equals the weight of 8 kiwi fruit and t pears. How many mangoes does a pineapple weigh? pls help me it's due tomorrow!​

I'm at a bookstore with $\$35$ in my pocket and a $20\%$-off coupon. what is the cost of the most expensive book i can buy with my money and the coupon? (assume that there are books of every possible price in the bookstore. it's a large bookstore! )