In adult Population or a city, 40% men and 30% women are married. What is the percentage of married adult population if no man marries more than one woman and no woman marries more than one man; and there are no widows and widowers?

Traditional Method - Let total no. of men = X and Total population be 100. Total women = (100 − X) Married men = 40 X/100 …(i) and Married women = (100 − X) × 30/100 …(ii) But, No. of married men = No. of married women. (as per conditions given) So, from (i) and (ii) X = 300/7 So, married Men = 300/7 X 40/100 = 120/7 and Married women = 120/7. Total married population = Men + Women = 240/7 Required percentage = 240/7 % = 342/7 %. So the correct option is (c). Alternative method: No man marries more than one woman and no woman marries more than one man. It means the Number of married men = Number of married women = 120 (let). Married adult population = 240. Number of men = 120×100/40 = 300 and Number of women 120 × 100/30 = 400. So, total population = 300 + 400 = 700. Required percentage 240×100/700 = = 240/7 % = 342/7 %