a number is increased by 11 % and then reduced by 10 % . after these operations , the number :
"let the original number be 100 . then , the new number = 100 × 1.1 × 0.9 = 99 i . e . the number decreases by 1 % . answer b"
divide(multiply(add(11, const_100), subtract(const_100, 11)), const_100)