how many multiples of 9 are there between 1 and 50 , exclusive ?
"5 multiples of 9 between 1 and 50 exclusive . from 9 * 1 upto 9 * 5 , ( 1 , 2,3 , 4,5 ) . hence , 5 multiples ! correct option is a"
add(divide(subtract(50, 1), 9), const_1)