how many numbers from 13 to 76 are exactly divisible by 10 ?
"option ' b ' 13 / 10 = 1 and 76 / 10 = 7 = = > 7 - 1 = 6 numbers"
add(divide(subtract(multiply(floor(divide(76, 10)), 10), multiply(add(floor(divide(13, 10)), const_1), 10)), 10), const_1)