CHALLENGES 18-20 Questions and Answers
CHALLENGE 18:
0...1...2...3...4...5...6...7...8...9...=1
Put the appropriate plus or minus signs between the numbers, in the correct places, so that the sum total will equal 1.
CHALLENGE 18 ANSWER:
0+1+2-3-4+5+6-7-8+9=1
CHALLENGE 19:
A man went into a jewelry store and bought a $75 chain, giving the clerk a $100 bill. He returned a few moments later and bought a new catch, giving the clerk a $20 bill and receiving $5 in change. Later, the bank told the store that both the $100 bill and the $20 bill were counterfeit. Ignoring markup, overhead, cost of merchandise, etc., how much money did the store lose?
CHALLENGE 19 ANSWER:
$120.00. The two counterfeit bills
CHALLENGE 20:
A man goes to visit his friend thirty miles away. He doesn't mind speeding, so he travels at 60 miles per hour and arrives in half an hour. On the way back, however, he has a little trouble with his car, and it takes him an hour to reach home. What was his average speed for the round trip?
CHALLENGE 20 ANSWER:
40 miles per hour. (This is deceptive. You do not add up the time and divide by two. You figure that he traveled sixty miles - there and back - in ninety minutes, or an hour and a half. That gives you the right answer.)