A boy runs for 20 minutes at a uniform speed of 18km/h .At what speed should he run for the next 40minutes. so that the average speed comes 24km/hr
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hope u understand the calculations yourself
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asujatha707:
thanq so much..
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1st case. d=vt
20min=1/3=0.3h, 0.3*18= 5.4km.
2nd case
40min=2/3=1.5h
1.5*d2
24= 5.4+d2/ 1.8h
43.2-5.4=d2
37.8=d2
** 12=37.8+ 5.4/1.8
12=43.2/1.8
12=24
2kmh^-1= speed of the the 2nd case..
20min=1/3=0.3h, 0.3*18= 5.4km.
2nd case
40min=2/3=1.5h
1.5*d2
24= 5.4+d2/ 1.8h
43.2-5.4=d2
37.8=d2
** 12=37.8+ 5.4/1.8
12=43.2/1.8
12=24
2kmh^-1= speed of the the 2nd case..
dont read this answer. its wrong k.
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