During the month of february, fabulous feet shoe mart sold 30 pairs of red loafers. after an ad campaign to boost sales, they sold 39 pairs in march. find the percent of increase in sales. 35% 30% 23% 18%

Percent increase = (new number - original number) / (original number) * 100
                           = (39 - 30) / 30* 100
                           = 9/30 * 100
                           = 0.3 * 100
                           = 30% increase <===