A blue plane, a red plane and a white plane are waiting to take off from an airport that has two runways. Planes must take off from the airport one at a time, but can take off from either runway. In how many ways can the three takeoffs be scheduled

Step-by-step explanation:

GIVEN: A blue plane, a red plane and a white plane are waiting to take off from an airport that has two runways. Planes must take off from the airport one at a time, but can take off from either runway.

TO FIND: In how many ways can the three takeoffs be scheduled.

SOLUTION:

As there are two runways on airport maximum plane can take off at a time.

Now,

Total number of ways when one plane takes off at a time.  

Total number of ways when two plane takes off at a time =  

Hence total number of ways in which three flights can be scheduled

  or  

step-by-step explanation:

if the four friends split the cost, p, of the pizza evenly, then each friend pays one-fourth of the cost of the pizza.

the expression is   or