math
posted by Andrea on .
Samantha opened a savings account and deposited some money into the account. The account pays an annual simple interest rate of 5%. After 9 years, the interest earned on the account was $1,800. How much money did Samantha deposit in the account?

I = PRT
1800 = P * 0.05 * 9
1800 = 0.45P
1800/0.45 = P
4,000 = P 
John is creating a Thanksgiving display at the store where he works, using only canned pumpkin and canned green beans. He needs to maintain a ratio of pumpkin to green beans of 5 to 2. If he wants to use a total of 112 cans, how many cans of green beans should he use?

2/7 = x/112
Cross multiply and solve for x. 
A small airplane flies from Big Lake to Pine City every day, with a 30minute layover in Summerville. The distance between Big Lake and Summerville is 675 miles, and the distance between Summerville and Pine City is 625 miles. If the airplane flies at an average speed of 200 mph, how long does the whole trip (including any stops) from Big Lake to Pine City take?

675 + 625 = 1300 miles
1300 / 200 = 6.5 hours
6.5 + 0.5 = ?