$600 at 18% interedt for four years

the answer to this is question would be 432

problem

you deposit some money into a bank account paying 4% simple interest per year. you received $72 in interest after 3 years. how much the deposit (principal) was?

result

the principal was $600.

explanation

find principal by using the formula i=p⋅i⋅t, where i is interest, p is total principal, i is rate of interest per year, and t is total time in years.

in this example i = $72, i = 4% and t = 3 years, so..

expression #3 is not equivalent. the others are.

pls ask