A test has five questions. To pass the test, at least three of the questions must be answered correctly. question > Find the probability that Mark guesses 4 questions correctly.

1/5

Step-by-step explanation:

Total Question no. 5

Three must be answer correctly so 3/5 to pass

  and 2/5 to fail  

So 1/5 because to pass the test he can answer it  correctly only one time

54 kilometers per hour

step-by-step explanation:

according to rules:

1 km = 1000 meter

which means that 1 meter = 1/1000 km

1 hour = 3600 second [ as 1 hour = 60 min = 60 *60 seconds ]

which means that 1 second = 1/3600 hour

therefore, 1 kilometer/hour =

thus to convert 15 meter per second to kilometer per hour, we multiply 15 to 3.6 kilometer/hour.

15 meter/second=   which is the required answer.

2(2x + 3) = -4 + 2(2x + 5)

4x + 6 = -4 + 4x + 10

4x + 6 = 4x + 6

4x - 6 + 6 = 4x - 6 + 6

4x = 4x

x = x

unlimited solutions.