The red semi-truck driver was new in town and didn't realize the danger in having the little pigeon sit in the driver's seat while he went in to check on a few things. Finding the key still in the ignition, the pigeon's big round eyes lit up with joy!
As the pigeon sped around the corner and over the curb, 6 chickens slid off the back of the truck. Not realizing the truck was so long, the pigeon rammed the back corner into a light pole, sending 1/3 of the remaining chickens to freedom. Their cages broken, these chickens crossed the road and escaped into Miss H's backyard. Because the seat was so low and the pigeon so short, he did not see the train crossing the tracks in front of him. Slamming on the brakes, the truck came to a screeching halt as 3/4 of the remaining chickens rapidly slid off the back of the truck and into the free world. Being a conscientious driver, the pigeon patiently waited for the train to go by. During this time, 5 more chickens managed to free themselves from their now broken cages. On the way around the block, the pigeon knocked over 2 fire hydrants and 1 bicycle, broke 2 windows and sent pedestrians running while 1/2 of the remaining chickens flew out of the truck to safety. By the time the pigeon made it around the block, bringing the truck back to its owner, the last 2 chickens had escaped, leaving the truck driver chickenless. how many chickens was the truck originally carrying?
There are 6 points in time to consider in this problem. At time 1, the truck had a full load of chickens. Let's call the number of chickens at this point C1.
At time 2, six chickens fell off the truck so the number of chickens remaining was
C2 = C1 - 6
At the third time point, 1/3 of the C2 chickens fell off and 2/3 of them stayed on the truck so the number of chickens remaining ...
This provides an example of working backwards to solve a word problem.