Edmond deposits $2500 in a bank at a simple interest rate of 4% p.a.
(a)How long will it take for Edmond to receive an amount of $3000?
(b)If the interest rate is increased to 5% p.a., find the amount Edmond will receive at the end of the deposit period in (a)

thanks

(a) my method is: press 2500(1+4/100) on the calculator, then it show 2600 on the "mon",
3000-2500=500 then 2600-2500=100
500/100=5(years)(方法比較複雜，請見諒）
(B) press 2500(1+5x5/100), and then get the answer 3125.

PS I am F3 and I am learning percentage too
but I have learning compound interest now.

Another method for (a):

Let y be the time that takes Edmond to receive $3000.
2500*4%*y = 3000-2500
100*y = 500
y = 5

.`. The time that takes Edmond to receive $3000 is 5 years.