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Math Puzzles & Brain Teasers

Spiders on the Web View Puzzle Solve Puzzle
 Hide all answers   View all answers   Print   Try the Quiz "Dad, where had you been?" asked Arthur."I had been to the attic, my son," replied Dad. "And do you know what I saw there? There was a big web with 14 spiders and flies on it.""How many spiders were there?" asked the little boy with curiosity."Well, there were a total of 92 legs on the web," answered Dad with a smile. "Now you can find out how many spiders were there by yourself. Can't you?"Can you help the little boy find out how many spiders were on the web in the attic? Answer: 4 Solution: Assuming 6 legs for each insect, 14 insects will have 84 legs. But, there are 92 − 84 = 8 extra legs. It is important to note that spiders have 8 legs and flies have 6 legs. So, there are 2 extra legs per spider on the web. Thus, the 8 extra legs belong to 4 spiders. Alternative Solution through Equations: Let s be the number of spiders and f be the number of flies. Then, s + f = 14; and 8s + 6f = 92. On solving the above two equations, we get 8s + 6 (14 − s) = 92; or 2s = 92 − (6 × 14). Thus, s = 4. Food for thought: Wish to try another puzzle similar in concept to this one? Then click here.   Try the Quiz :     Puzzles & Brain Teasers : Spiders on the Web 