Tuesday, February 24, 2009

Problems 1 through 4 of 2008 Team Round #3

These are just hints:

1) The total number of sandwiches can be divided by 7 with nothing left over. Divide total by 7, multiply the result by 2.

2) L = 4/3 W Area is LW (note: LW means L times W) LW = 300, but when you substitute L=4/3 W, you get a formula for W squared. Take the square root, you know W. Then use L=4/3 w to get L. Note: the problem asks for "length."

3) The smallest 3-digit number divisible by 11 is 110. Since 110 is divisible by 2 with nothing left over, it can't be the answer. Try 121, it meets all the conditions.
Another way, the answer has to be 1 plus a multiple of 60. It can't be 61, because 61 is not a 3-digit number. But it could be 120 plus 1, or 121. This is "educated guessing" I don't know any other way to do it. "Sixty" is the least common multiple of 2,3,4,and 5.

4) When an elevator goes from first floor to third floor, it really goes up 2 "spaces:" draw a picture. So, when it goes from first floor to 20th floor, it goes up 19 spaces.