Plane Speed = f(Latitude)

Take the circumference of the earth at the equator to be 24,000 miles. An airplane taking off at the equator and flying west at 1,000 miles per hour would land at exactly the same time that it started, and the sun would not move in the plane’s sky during that flight. (Work this out visually in your mind.) Now, can you find a formula so that the speed of a plane flying at any particular latitude and keeping up with the sun, is a function of that latitude: speed = f(x°)?

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Muffins

Milly Miffin made one muffin more than Molly’s mother made, and Milly Miffin’s mother made one muffin more than Molly made; and Molly’s mother and Milly and Milly’s mother and Molly made 50 muffins (total), but Molly’s mother and Milly made 4 muffins more than Milly’s mother and Molly made. So murmur how many muffins Milly made.

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Audio Equipment

Sue got a lot of money for graduation from a mysterious, rich aunt that she’d never known she had. Her first thought was AUDIO EQUIPMENT, but then she figured she really ought to put it away for a rainy day. She divided it into two parts. One part had $250 more than the other part. She invested the smaller part at 6% interest, and the larger part at 8%. A year later, the total interest she had accumulated was $72.50. How much money did she get from her mysterious, rich aunt for graduation in the first place?

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