সঠিক উত্তর হচ্ছে: op1/30
ব্যাখ্যা:
Let A be event of selecting a number divisible by 3. B be the event of selecting a number divisible by 7.
A = { 3, 6, 9, 12, 15, 18, 21, 24, 27, 30 }, so n(A)=10
B = { 7, 14, 21, 28 }, n(B)= 4
Since A and B are not mutually exclusive So :