Answer this please...

One of every 20 customers reports poor customer service on your company’s customer satisfaction survey. you have just created a new process that should cut the number of poor customer service complaints in half. what percentage of customers would you expect to report poor service after this process is implemented? 1.) 5% 2.) 10% 3.) 2% 4.) 2.5%

Can someone explain to me how to do

Sally deposited money into a savings account paying 4% simple interest per year.the first year,she earn $75 in interest.how much interest will she earn during the following year?