MathsF.2,,plz help(要式)

1)Mr.Mak deposits$30000in a bank at6.5%p.a.simple interest rate.Mrs.mak deposits$50000in another bank at7%p.a.simple interest rate.
(a)How much interest will they earn altogether one year later?
(b)Find the total amount they will get four years later.
2)Mr.lee deposits$6000in a bank at an interest rate of 4%p.a.for 3 years.Mrs.Lee depoits a sum of money in another bank at an interest rate of 5%p.a.for 2 years.If they earn the same simple interest,how much does Mrs.le deposit?