Grade 12 Data Management?

Numbers from 0 to 99 inclusively are formed by choosing the units digit and the tens digit ( which may be 0) at random from the numbers 0,1,2,.....,9. calculate the probabilty that:


a) the random number is even


b) the random number is greater than 85


c) the random number is less than 33


d) the tens digit and the units digit are consecutive numbers; eg. 23

Grade 12 Data Management?
You can easily enumerate the possibilities.





They are 100 total possibilities, half of them are even





a = 50%





14 of the 100 are greater than 85





b = 14%





33 of the 100 are less than 33





c = 33%





01 12 23 34 45 56 67 78 89





they are 9 (unless you want the ones that go down as well)





d = 9%
Reply:A) 50% - 100 numbers, 50 of which are even, and 50 of which are odd...





B) 10% * 40% + 10% = 14% {86, 87, 88, 89, and 90-99}





C) 33% {0 to 32} is 33 numbers.





D) {01, 12, 23, 34, 45, 56, 67, 78, 89} of 100 numbers = 9%

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