Question

In a certain factory producing bolts, the chance of producing a defective bolt is 1/500. the bolts are supplied in a packet of 10. calculate the approximate number of packets containing two defective bolts in a consignment of 20,000 packets.

A. 8
B. 4
C. 9
D. 3

Answer 1

To calculate the approximate number of packets containing two defective bolts in a consignment of 20,000 packets, calculate the probability of getting exactly two defective bolts in a packet and then multiply it by the total number of packets. Round the result to the nearest whole number.

So, the closest option is: A. 8

Step-by-step explanation:

To calculate the approximate number of packets containing two defective bolts in a consignment of 20,000 packets:

1. Calculate the probability of getting exactly two defective bolts in a packet. Since the chance of producing a defective bolt is 1/500 and there are 10 bolts in each packet, the probability is given by (1/500)^2 * (499/500)^8 * 10C2, where 10C2 is the combination of 10 bolts taken 2 at a time.
2. Calculate the probability of getting two defective bolts in each packet. Since there are 20,000 packets, the probability is given by the product of the probability calculated in step 1 and 20,000.
3. Round the result to the nearest whole number to get the approximate number of packets containing two defective bolts.

The approximate number of packets containing two defective bolts in a consignment of 20,000 packets is 3 (option D).