if 7 spiders make 7 webs in 7 days , then 1 spider will make 1 web in how many days ?
let the required number days be x . less spiders , more days ( indirect proportion ) less webs , less days ( direct proportion ) spiders 1 : 7 webs 7 : 1 1 x 7 x x = 7 x 1 x 7 = > x = 7 answer is 7
multiply(1, 7)