Answer to April 23, 2001 Problem

The Sequences Problem
Determine what is missing in the following two sequences:

Sequence #1: What is the missing number in this sequence:
43, 41, 37, 31, 29, ___, 19, 17

Sequence #2: What letter comes next in the following sequence:
A, S, D, F, G, H, J, ___


Solution:

Sequence #1: The answer is 23 or 25.

To get 23, it is a list of consecutive prime numbers in descending order (23 is missing).

To get 25, begin with 43, then subtract 2 to get the next term, subtract 4 to get the next term, then subtract 6 to get the next term, then repeat subtracting 2, then 4, then 6, then 2, ...

Sequence #2: The answer is K or U.

To get K, look at the second row of your computer keyboard (which was the intended answer).

However, three problem solvers sent in U. The letters of the alphabet run in a circle. From A move forward 18 to S, then move 11 to D, then move 2 places to F, then 1 to G. Then go 1 to H, then move 2 to J, then move 11 to U.


Correctly solved by:

1. Rick Jones Kennett Square, Pennsylvania
2. Bob Hearn Winchester, Virginia
3. Jaime Garcia Winchester, Virginia
4. Jonathan O'Neill Winchester, Virginia
5. David Marut Winchester, Virginia
6. Jason Farmer Winchester, Virginia
7. Chip Schweikarth Winchester, Virginia
8. George Gaither Winchester, Virginia
9. Tom Kelley Winchester, Virginia
10. David Powell Winchester, Virginia
11. Keith Mealy Cincinnati, Ohio
12. Ricki Stern Highland Park, New Jersey
13. Richard Johnson La Jolla, California
14. Joe Heintz Manchester, Tennessee
15. ---------- Feltham, Middx, United Kingdom
16. Bill Hall Wellington, Florida
17. Erin McGinnis Winchester, Virginia
18. Izzy Kushner Closter, New Jersey
19. Robert Bennington's
Grade 7 Math Class 		High River, Alberta, Canada
20. John C. Funk Ventura, California