Question

An integer is chosen from 1 to 50. Find the probability that it is multiple of 5 or multiple of 7.

Answer 1

Final Answer : 8/25

Steps:
1) An integer is chosen from 1 to 50:
= > Total no. of outcomes, n(S) = 50

2) Numbers which are multiple of 5 :
5,10,....50 : 10 terms
Numbers which are multiple of 7 :
7 , 14 ..... 49 : 7 terms.

3) LCM : (7,5) = 35
35 is common in both multiples :

Hence, Total no. of Favourable terms ,n(E) : 10+7-1=16

Therefore, Probability of getting number which is multiple of 7 and 5 :

n(E)/n(S) = 16/50 = 8/25 .

Answer 2

Answer:

Final Answer: 8/25

Steps:

1) An integer is chosen from 1 to 50: = > Total no. of outcomes, n(S) = 50

2) Numbers which are multiple of 5: 5,10,....50 : 10 terms

Numbers which are multiple of 7: 7,14 .. 49 : 7 terms.

3) LCM: (7,5) = 35 35 is common in both multiples :

Hence, Total no. of Favourable terms ,n(E) : 10+7-1=16

Therefore, Probability of getting number which is multiple of 7 and 5:

n(E)/n(S) = 16/50 = 8/25.