Question

9. Two numbers are selected at random from
1, 2, 3, ...... 100 without replacement. The
probability that the minimum of the two
numbers is less than 70 is
30
-
31c₂
3) 100c
31c
1) 100cm
30C
100C
2)1-
4)1-
100c₂
C₂
time If​

Answer 1

Answer:

No of ways of selecting two number = 100C _ 2

Now, no. of ways of selecting two numbers, of which minimum is less than 70 is same as saying subtracting total number of ways of  both numbers greater than 70.

∴ Probability = 1−30C _2/ 100C  _2  

 [Total probability =1]

(Probability of selecting two object from 30 object to that of 100 object =  

30C  _2/100C _2