Letter Series with Blanks

1. Count the places, letters and blanks together. The total is usually the block length times the number of copies (20 = 4 × 5, 21 = 3 × 7). 2. Find the block length: look for where the first letter, or the first two letters, come back. Try the lengths that divide the total. 3. Build the block from the letters printed in each position across all the copies. 4. Read the blanks from left to right using the block. 5. Fast route: once the block is known, fill only the first two blanks and strike out the options that disagree; check the last blank of whatever is left.

1. Count the places. With 12 places, the block is 2, 3, 4 or 6 letters long. 2. Try the shortest length first. Write the block from the first copy that has no blank in it, or from the printed letters at the same place in each copy. 3. Test every printed letter. A block is right only if each printed letter sits where the block says it should. 4. Prefer the shortest block that fits. With only two letters, a longer block can sometimes be made to fit too; SSC's answer is the series with the shortest repeating block.

1. Split the series into equal blocks, usually four blocks of five or four of four. 2. Compare the blocks place by place. Most places hold the same letter in every block. 3. Find the moving place: its letters run on, such as J, K, L, M or T, S, R, Q. 4. A variant: in some series every place moves, each by its own step. Read each place down the blocks as a letter series. 5. Fill the blanks block by block, using the fixed letters and the next letter of the moving place.