A number is randomly chosen from the first 100 positive integers. What

Question

A number is randomly chosen from the first 100 positive integers. What is the probability that it is a multiple of 3?

(A) 32/100

(B) 33/100

(C) 1/3

(D) 34/100

(E) 2/3

kanakdaga · Accepted Answer

A number is randomly chosen from the first 100 positive integers. What is the probability that it is a multiple of 3?

EASY FORMULA FOR SUCH QUESTIONS:

1+

Here increment = 3 
range = 1-100 (first 100 positive numbers)

Answer = 1+   
= 1+ 96/3 
= 1+ 32
= 33

PLEASE KUDOS IF THIS HELPED! :D

UB001 · Answer

Given :  A number is randomly chosen from the first 100 positive integers.
 Question :  What is the probability that it is a multiple of 3?

We need to find the number of multiples of 3 in first 100 POSITIVE integers.
By  AP  we have
 Tn = a + (n-1)*d  (where, Tn = 99; a= 3; d =3)
99 = 3 + (n-1)* 3
96 = (n-1)* 3
32 = (n-1)
  n = 33

Therefore, the probability that chosen number in first 100 is a multiple of 3 is given by
 = No. of favorable outcomes / Total no. of outcomes 
 = 33 / 100 
 Answer Option B is Correct.

DisciplinedPrep · Answer

Total number ways of choosing a number from the first 100 positive integer = 100 ways
Total number of multiples of 3 between 1 and 100 is 33, i.e. 3, 6, 9....99 = 33 multiples
Hence, the number ways of choosing a multiple of 3 from the first 100 positive integer = 33 ways
Therefore, when a number is randomly chosen from the first 100 positive integers, the probability that it is a multiple of 3 = 33/100

Hence, the Correct Answer is Option B. 33/100

sakshamjinsi · Answer

No of Possibilities = 100
Multiples of 3 from 1 to 100 = 33

Hence, Probability = 33/100

Archit3110 · Answer

33 multiples of 3 from 1 to 100
so 
33/100 would be the P of multiples of 3 in between 1 to 100

IMO B

BrentGMATPrepNow · Answer

The multiples of 3 are as follows: 3, 6, 9, 12, .....96, 99

Notice that: 
3 = 3( 1 )
6 = 3( 2 )
9 = 3( 3 )
12 = 3( 4 )
.
.
.
96 = 3( 32 )
99 = 3( 33 )

So, we can see that there are  33  multiples of 3 between 1 and 100.

So, P(chosen number is multiple of 3) =  33 /100

Answer: B

Cheers,
Brent

GMATinsight · Answer

Probability = Favourable outcomes / Total Outcomes
Total Outcomes = 100
i.e. Denomitaor can be 100 or a factor of 100
  i.e Options C and E are out  
Favourable outcomes = multiples of 3 from 1 to 100 =   = 33 (Greatest integer function of 100/3)

i.e. Probability = 33/100

Answer: Option B

bumpbot · Answer

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A number is randomly chosen from the first 100 positive integers. What

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