The probability of Sam passing the exam is 1/4. The probability of Sam passing the exam and Michael passing the driving test is 1/7. What is the probability of Michael passing his driving test?  Select.
A) 1/24.
B) 1/2.
C) 4/7.
D) 2/3.
E) 2/5
1/4 *1/m= 1/7 , 1/m = 4/7   Answer 4/7.
<result>C</result>
The probability of Sam passing the exam is 1/4. The probability of Sam passing the exam and Michael passing the driving test is 1/7. What is the probability of Michael passing his driving test?