SOLUTION: David had $4000 invested for one fourth of a year ar a simple interest rate of 6.1%. how much interest did he earn? 2. Tori invested $8000 in money market funds. Part was i

Question 230643: David had $4000 invested for one fourth of a year ar a simple interest rate of 6.1%. how much interest did he earn?

2. Tori invested $8000 in money market funds. Part was invested at 5% simple interest, and the rest at 7% simple interest. at the end of 1 year, tori had earned $496 in interest. How much did she invest in each fund?
3. The Clark family went sailing on a lake. Their boat averaged 6 kilometers per hour. The Rourke family took their outboard runabout for a trip on the lake for the same amount of time. Their boat averaged 14 kilometers per hour. The Rourke family traveled 20 kilometers farther than the Clark family. How many hours did each family spend on their boat trip?
Answer by rfer(16322) (Show Source): You can put this solution on YOUR website!
1
A=Prt
A=4000*.061*.25
A=$61
2)
.07x+.05(8000-x)=496
.07x+400+.05x=496
.12x=96
x=$800 at 7%
8000-x=7200 at 5%

RELATED QUESTIONS
david had $4000 invested for one fourth of a year at a simple interest of 6.1%. how much... (answered by rfer)

David had $4000 invested for one fourth of a year at a sample interest rate of 6.1% How... (answered by stanbon)

I am having to write an algebraic equation for each problem and solve it. I am not sure... (answered by mananth)

David had $4000 invested for 1/4 of a year at a simple rate of 6.1%. How much interest... (answered by rfer)

$4000 invested for 1/4 of a year at a interest rate of 6.1%, how much interest did he... (answered by lagapa)

Katie invested a total of $4000, part at 3% simple interest and part at 4% simple... (answered by josmiceli)

Katie invested a total of $4000, part at 4% simple interest and part at 5% simple... (answered by ankor@dixie-net.com,stanbon)

Alex invested $6000, part at 6% simple interest and part at 4% simple interest for a... (answered by mananth)

HUANG invested $9000 in mutual funds and bonds. the mutual fund earned 11% simnple... (answered by mathstutor458)