# Christmas Delivery Drivers Quiz Puzzle Answer

With more and more people buying goods online the number of delivery drivers has increased, and the pressure on the delivery companies to get parcels to the correct place on time has also increased. At Christmas the situation gets even more pressurised and the logistics managers must keep on their toes.

A local delivery company has three depots named, rather confusingly, Day, Night and Morrow, with one logistics manager in overall charge of all three.

At 8.00 AM on 18th December he issued the following instruction:

DRIVERS NOW AT DAY MUST GO TO NIGHT TO MORROW. DRIVERS NOW AT MORROW MUST GO TO DAY TO NIGHT. DRIVERS NOW AT NIGHT MUST GO TO MORROW TO DAY.

At 6.00 PM he sent the following message:

ORDERS GIVEN THIS MORNING FOR DRIVERS TO GO TO NIGHT ARE CANCELLED FOR DRIVERS WHO HAVE NOT YET MOVED.

At one minute to midnight he instructed:

DRIVERS WHO WENT TO DAY TO NIGHT WILL RETURN AT 6.00 AM TO MORROW.

Day is the period of time before 6.00 PM and Night is from 6.00 PM to midnight.

On 20th December there were 26 drivers at Day, 24 drivers at Night and 50 drivers at Morrow.

Assuming that all instructions that have two interpretations will be interpreted by half the drivers one way and half the drivers the other way, what was the distribution of drivers at 8.00 on 18th December?

Let the distribution of drivers on 18th December be x at Day, y ay Night and z at Morrow.

After the first instruction:

x/2 drivers think they should go to Night tomorrow,

x/2 drivers think they should go to Morrow tonight,

y/2 drivers think they should go to Day tomorrow,

y/2 drivers think they should go to Morrow today,

z/2 drivers think they should go to Day tonight,

z/2 drivers think they should go to Night today,

At 6.00 PM there are x drivers at Day, y/2 + z/2 drivers at Night and y/2 + z/2 drivers at Morrow.

As a result of the second instruction:

x/4 drivers who were going to go to Night now stay at Day

x/4 drivers who were going to go to Morrow now stay at Day

z/4 drivers who were going to go to Day now stay at Morrow

At midnight there are 3x/4 + z/4 drivers at Day, y/2 + z/2 drivers at Night and x/4 + y/2 + z/4 drivers at Morrow.

As a result of the third instruction:

z/8 drivers return from Day to Morrow

z/4 drivers return from Night to Morrow

At midnight on 19th December there are x/2 + y/2 + z/8 drivers at Day (totalling 26), x/4 + z/4 drivers at Night (totalling 24) and x/4 + y/2 + 5z/8 drivers at Morrow (totalling 50).

From this 32 drivers started at Day, 4 drivers started at Night and 64 drivers started at Morrow.