August 2026
Problem of the Month

Six-term Sequence

In the six-term sequence A, B, C, D, E, F, each term after the first three is the sum of the previous three terms.

If D = 15 and E = 24, determine the value of A.

Solution to the Problem:

A = 6.

E = D + C + B
D = A + B + C

24 = 15 + B + C
15 = A + B + C

9 = 15 - A
so A = 6

Correctly solved by:

1. Colin (Yowie) Bowey	Beechworth, Victoria, Australia
2. Davit Banana	Istanbul, Turkey
3. Dr. Hari Kishan	D.N. College, Meerut, Uttar Pradesh, India
4. Seth Cohen	Concord, New Hampshire, USA
5. Mrs. Painter's Honors Precalculus Class	Broome High School, Spartanburg, South Carolina, USA

Send any comments or questions to: David Pleacher