72 67 66 61 60 . . . ?
"sequence = 72 67 66 61 60 55 there is 2 series : 1 st series = 72 66 60 ( decreasing by 6 ) 2 nd series = 67 61 55 ( decreasing by 6 ) answer : d"
divide(multiply(add(72, divide(67, 66)), 61), const_100)