Kevin, Charles, Larry and Alex are in a room that’s about 110 feet long. In front of them are 5 balls which are exactly 100 ft from the exit. The balls are yellow, purple, green, red and blue, respectively. Each man must carry a ball to the exit. After traveling 20 ft a ball will change color twice. The sequence of color changes is always the same: yellow, purple, green, red, and blue.
At 80 ft Kevin’s ball is red. At 40 ft Larry’s ball is purple. At 60 ft Charles’ ball is blue At 100 ft Alex’s ball is purple.
The remaining ball was blue. Here’s a table of each ball and the color it changes to at 20, 40, 60, 80 and 100 ft. Kevin’s started out yellow, Larry’s was green, Charles’ was red and Alex began with a purple ball, leaving blue as the one nobody picked.
Find a six-digit number containing no zeros and no repeated digits that satisfies the following conditions:
1. The first and fourth digits sum to the last digit, as do the third and fifth digits. 2. The first and second digits when read as a two-digit number equal one quarter the fourth and fifth digits. 3. The last digit is four times the third digit.
If you call the number ABCDEF, then you get the following equations.
1. A + D = F and C + E = F 2. AB = DE / 4 3. F = 4 × C
The only numbers that work for C and E are 2 and 6 or 4 and 8, and in order to make F a single-digit number, we can deduce that C = 2, E = 6 and F = 8.
So far, our number is AB2D68.
We know A + D = 8 so A and D are both odd numbers. The only odd number less than 8 that we can use for D to make one-quarter of two-digit number D6 also be a two-digit number is 7, so D = 7 and A is 1. This makes the two-digit number AB 19.
5 minutes. It takes each machine 5 minutes to make a shirt, so if you have all 100 machines running at the same time, they’ll produce the 100 shirts in 5 minutes.