Respuesta :

Answer:

Part 18) Option H None of the above

Part 19) Option B 22

Step-by-step explanation:

Part 18) we know that

The numbered cards are [10,11,12,13,14,15,16,17,18,19]

The numbers primes are [11,13,17,19] (total 4 numbers]

If Brian remove three cards whose numbers are primes

then

In the hat only will remain one card with a number prime and the total cards in the hat will be 7 cards

therefore

If one card is drawn at random from the hat, the probability that its number is a prime is equal to

P=1/7

Part 19) we know that

Faysal estimated that the total hours to complete the exam is 10 hours

He completes an average of 12 questions an hour for the first four hour

so

For the first 4 hours he completes 12*4=48 questions

Remaining questions is equal to 180-48=132 questions    

so

To find the mean divide the remaining questions by the remaining time (6 hours)

132/6=22 questions/hour