23. दुई अङ्कको एउटा सङ्ख्या त्यसका अङ्कहरूको योगको चार गुणा छ । यदि अङ्कहरूको गुणनफल 18 भए त्यो सङ्ख्या र त्यसको विपरीत सङ्ख्या बिचको भिन्नता पत्ता लगाउनुहोस् । A number of two digits is equal to four times the sum of the digits. If the product of the digits is 18 then find the difference between the number and its reversing number.