Question

A man borrows Rs 18000 at 5% per annum compound interest .If he repays Rs 6000 at the end of the first year and Rs 8000
at the end of the second year; how much should he pay at the end of the 3rd year in order to clear the account?

Answer 1

x + 8000(1.05) + 6000(1.05)^2 = 1800(1.05)^3
...
....
x =5822.25

( For these I make a "time graph"
on a line, mark 0 (now), year 1, year 2 , and year 3
Place 18000 above the "now"
place 6000 at 1, 8000 at 2, and x at 3

"move" all monies to position 3 )