Echo Numbers
How to Submit
Send your answers along with full name, any prior I.Q. test scores, and $5 fee via PayPal to skillitani@gmail.com. This test allows three attempts, but only the first will be marked as official.
Instructions
There is no time limit. A pocket calculator, pencil, and paper are allowed and encouraged. Reference aids will not be needed.
Find the solution that best replaces the question mark(s) in each series.
The Series
Part I
1) 3, 6, 12, 24, 48, 96, ?
2) 3, 6, 10, 15, 21, 28, ?
3) 3, 6, 9, 15, 21, 40, ?
4) 3, 6, 18, 72, 360, 2160, ?
5) 3, 6, 15, 42, 123, 366, ?
6) 3, 6, 18, 108, 1944, 209952, ?
7) 3, 6, 7, 20, 11, 42, ?
8) 3, 6, 19, 78, 393, 2362, ?
9) 3, 6, 456, 789987, 654, 6, ?
10) 3, 6, 4, 8, 6, 0, 7, 2, ?
11) 3, 6, 18, -12, 6, -2, -12, ?
12) 3, 6, 33, 36, 63, 66, ?
Part II
13) 36, 612, 918, 1224, 1530, 1836, ?
14) 36, -3, 72, 5, 144, -7, ?, ?
15) 36, 6, 1, 1/6, ?, ?, 1/1296
16) 36, 216, 432, 1296, 11664, 69984, ?
17) 36, 39, 63, 279, 2223, 19719, ?
18) 36, 81, 169, 324, 576, 961, ?
19) 36, 3, 6, ?, -24, -57, -54
20) 36, 3/23, 3/213/2, ?, 3/211/21/213/211/2
21) 36, 189, 7218, 11218, 1613, 1811, ?
22) 36, 72, ?, 108, -36, 144, ?
23) 36, 33, 27, ?, -42, -105, -171
24) 36, 18, 12, 9, ?, 6, 5.1428571429, ?
Part III
25) 3, 5, 2, 6, 1, 7, ?
26) 3, 33, 363, 3993, ?
27) 3, 63, 363, 3363, 33363, 333363, ?
28) 3, 63, 69, ?, ?, ?, 123
29) 3, 63, 3636, 63636, 6363636, 66363636, 3663636366, ?
30) 3, 63, ?, 4815, 80226, 694647, 2597598
31) 3, 34, 534, 5346, 75346, 753468, ?
32) 3, 3, 2 1/2, ?, 1 8/13, 1 1/3, 1 1/8
33) 3, 36, 102, 201, ?, ?, 696
34) 3, 4, 10, ?, ?, 74666872
35) 3, 5, 7, 3, ?, ?, 3, 5
36) 3, 12, 4, 90, 78, 5, ?