сума feeded a total simple legage of rs . 100 in the rate of 5 p . c . p . a . in 4 years . what is the sum ?
"sol . главницата  rs . [ 100 * 100 / 5 * 4 ]  rs . [ 10000 / 20 ]  rs . 500 . отговор c"
divide(divide(multiply(100, const_100), 5), 4)