Need Urgent math help with Mr.Thomas’ investment

Need Urgent math help with Mr.Thomas’ investment

Mr. Thomas invested an amount of $13,900 divided in two different schemes A and B at the simple interest rate of 14% p.a. and 11% p.a. respectively. If the total amount of simple interest earned in 2 years be $3508, what was the amount invested in Scheme B

A sum fetched a total simple interest of $4016.25 at the rate of 9 p.c.p.a. in 5 years. What is the sum

How much time will it take for an amount of $450 to yield $81 as interest at 4.5% per annum of simple interest?

Reena took a loan of $1200 with simple interest for as many years as the rate of interest. If she paid $432 as interest at the end of the loan period, what was the rate of interest?