6x3=15+3=18 explain the calculation

Which of these number is main idea? plz i need this quick (1) sundays aren’t what they used to be—a day for reading and rest. (2) in the past, most stores and businesses were closed on sunday. (3) liquor was unavailable by law. (4) worship and family time recharge people’ s energy for the week ahead. (5) today, religious services and family meals may still be on the agenda. (6) nevertheless, people use sundays to catch up on errands, watch sports on tv, or work around the house or at their job. (7) at present, over thirty-one states permit sales of alcohol on sunday. (8) stores stay open because sunday shopping offers additional profit. (9) there’ s even a bank with an advertising campaign based on doing business on sundays. (10) and circulation of the sunday newspaper has dropped dramatically, with people saying they no longer have time to read.