Question 37242
<pre><font size = 4><b>What is the next number in this sequence and 
how do you get it?

1, 2, 5, 10, 4, 8, 20, 40,? 

The sequence starts with 1
Step#
  1.  To get from 1 to the next number 2, we multiply by 2.
  2.  To get from 2 to the next number 5, we add 3.
  3.  To get from 5 to the next number 10, we multiply by 2.
  4.  To get from 10 to the next number 4, we subtract 6.
  5.  To get from 4 to the next number 8, we multiply by 2.
  6.  To get from 8 to the next number 20, we add 12
  7.  To get from 20 to the next number 40, we multiply by 2.
  8.  ?????????????

Steps 1, 3, 5, and 7 are all "multiply by 2"

Step 2 is "add 3"
Step 4 is "subtract 6"
Step 6 is "add 12"

So looking at that step 8 should be "subtract 24"

So the next term of

1, 2, 5, 10, 4, 8, 20, 40, ?

should be gotten by subtracting 24 from 40, getting 16. 

1, 2, 5, 10, 4, 8, 20, 40, <u>16</u>

Answer: 16

Edwin
AnlytcPhil@aol.com</pre>