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a uniform speed of 100 m/minute. After one minute, a policeman runs after theA thief runs withthief to catch him. He goes with a speed of 100 m/minute inspeed by 10 m/minute every succecding minute. After how many minutes thecatch the thief. What value is depicted in this question? |
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Answer» Thief speed=100m/mintime taken by police before catching the thief= xthen the time of thief being catched= x+1as the police increases his speed 10 m/min every succeeding minute,his time taken forms an ap- 100,110,120...... distance of thief=time*speed=100*(x+1)-----------------1 distance covered by police=sum of x terms of the apsn=x/2 (2(100) + (x-1) 10)sn=x(100+5x-5)sn=95x-5x square---------------2as the distance covered by police and thief are same,1=295x-5x square=100*(x+1)95x-5x square=100x + 1005x square-5x-100=0xsquare-x-20=0 if we solve this equation,we will get x= -4 and x=5as time cannot be negative, 5 is the right answer.thus the time taken by the police to catch the thief=5 mins. |
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