Wednesday 31 March 2010

DAY 221
What is the smallest number that is evenly divisible by 1, 2, 3, 4, 5, 6, 7, 8, and 9?

Answer:

2,520........The answer is found by finding the Least Common Multiple of the numbers 1 through 9.

Wednesday 17 March 2010

DAY 220

TUNNEL VISION
(GAMES Magazine---Sam na Sam)

A train 125 yards long traveling at 40 miles per hour enters a long tunnel. Just as the last car is completely inside the tunnel, a man begins walking from the end of the train to the front. He walks at 5 miles per hour and reaches the front of the train just as it emerges from the tunnel into daylight. How long is the tunnel?

Answer:

The tunnel is 1,125 yards long. If x = the length of the tunnel, the man walks x yards at 45 miles per hour (the combined speed of the train and his walking). He walks this distance in the same time the train travels x - 125 yards at 40 miles per hour. Using the D = RT formula, since T is the same, x/45 = (x - 125) /40. This equation solves to x = 1,125.

Monday 15 March 2010

DAY 219
Two watches are started at 11:00 a.m. One is gaining 3 minutes per hour, and one is losing 3 minutes per hour. At what time will the fast watch be one hour ahead of the slow one, and what will be the times on the two watches?

Answer:

At 9:00 p.m.---ten hours later---the two watches will be one hour apart. The slow watch will show 8:30 and the fast watch 9:30.