Farmer Jones paid $150 for one cow and $50 for the other. He sold them for $210, clearing 5 per cent.

This puzzle makes no pretense at context. It is not even pseudocontext, yet it is a excellent use for algebraic reasoning and guess and check, or systems of equations if you were so minded. It is interesting to me to think that Loyd's Puzzles (ca 1910) were published in the newspaper for the common man, for the farmer, for the factory worker, for the clerk, for the uneducated, for everyone - as challenges.

Math isn't fun. It's satisfying.

1.1x + .90y = 210

1.05( x + y) = 210 ==>> x + y = 200 ==>> x = 200 - y

1.1(200-y) + .9y = 210

220 - 1.1y + .9y = 210

-.2y = -10

y = 50

x = 150

return to the Cattle Puzzle.

## Thursday, January 1, 2009

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Do they ask for the price of each, or just the original price?

ReplyDelete210/1.05 = $200 is easier.

The answer in the book lists the two prices.

ReplyDelete