If 4 spiders make 4 webs in 4 days, then 1 spider will make 1 web in how many days?  Answers:  A) 1  B) 3  C) 5  D) 4  E) 6

Rationale: "explanation : let the required number days be x . less spiders , more days ( indirect proportion ) less webs , less days ( direct proportion ) spiders 1 : 4 | | : : 4 : 1 webs 4 : 1 | = > 1 * 4 * x = 4 * 1 * 4 = > x = 4 answer : d"
Answer: D