Simple Interest questions... just 5 Qs =)?

please help me. im very confused with these... there are more but i think if i ask for help in SOME questions then i can do the rest by myself..





1) Find the simple interest rate for a sum to three times itself in 10 years time.





2) In how many years will a sum of money double itself at 12%p.a. simple interest?





3) Jane puts $2500 on August 4, 1981 in a saving bank. If the rate of simple interest is 12.5% p.a. What will be the amount on June 28, 1983??





4) Divide $5000 into 2 parts such that the simple interest on one part at 10% for 3 years, should be equal to that on the other at 12% for 2 years.





last one..





5) $100 000 is put on 28th of April in a 6 month fixed deposit account at 5% p.a and is withdrawn on 8th December in the same year. Find the total interest obtained, the overdue interest being calculated on daily basis and at 3.5% p.a.





Thanks so much.. please show working out so i know how to do the other similar questions.|||Hello!





Remember simple interest is Interest=principlexratextime





Principal is the amount of money deposited, and the rate is the amount of percentage increased per year, the time is the amount of time the money is inside it.





If you need help with any one of these questions feel free to IM me or email me and i'll be glad to help anyone!





Hope this helps!





Sincerely,


Mr.Math