TICKETS NUMBERED

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TICKETS NUMBERED

by francoisph » Wed Jun 09, 2010 2:30 pm
Hi,

please could you explain?

Rafle tickets numbered consecutively from 101 through 350
are placed in a box. What is the probability that a ticket selected at random will have a number with a hundreds digit of 2?



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by gmatjedi » Wed Jun 09, 2010 3:50 pm
200, 201...299

so total of 299-200+1 digits with a 2 in the hundred digits= 100
total number from 101-350= 350-101+1=250

therefore, 100/250 =40%

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by jeffedwards » Wed Jun 09, 2010 4:16 pm
101 - 199 = 99 Tickets
200 - 299 = 100 Tickets
300 - 350 = 51 Tickets

100 / (99+100+51) - Number of choices that meet desired criteria over total number of choices
100 / 250
10 / 25
2 / 5