Question

In a box there are 10 non-defective bulbs and some defective bulbs. If the probability that a bulb selected at random from the box to be defective is 2/7, then find the defective bulbs

Answer 1

Answer:

X = 4

Step-by-step explanation:

Non defective bulb : A= 10

Defective bulb : B= X

n (s) = X+ 10 n (B) = X

n (A)= 10

P (B) = X /x+10 = 2/7 { given}

X/x +10 = 2/7

1. 7x = 2x +20
2. 5x =20
3. X = 20/5

X = 4 ans