Question

38.In a group of 20 persons, there are 5 graduates. If 3 persons are selected at random
a) 1/120 b) 15/108 C) 17114
from the group, the probability that at least one is graduate is
a) 115/228 b) 135/228 c) 225/228 d) 137/228​

Answer 1

Answer:

option d is correct if my calculation is right

137÷228 which means 0.600

Step-by-step explanation:

20 person

5 graduate

and 3 selected

condition is atleat one is graduate

so,

step1:- 5c1 ×15c2÷20c3 = 525÷1140=0.4605

step2:-5c2×15c1÷20c3 = 150÷1140=0.1315

step3:-5c3×15c0÷20c3 = 10÷1140=0.008771

step 1+2+3 .i.e 0.4605+0.1315+0.008771=0.600/137÷228