SOLUTION: Joshua likes to read. He read 6 books when he was 6 years old. Every year he doubled the number of books he read the previous year. How many total books did he read between the age

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Question 1102348: Joshua likes to read. He read 6 books when he was 6 years old. Every year he doubled the number of books he read the previous year. How many total books did he read between the ages of 6 and 10?
Found 3 solutions by Lightning_Fast, josmiceli, richwmiller:
Answer by Lightning_Fast(78) About Me  (Show Source):
You can put this solution on YOUR website!
Let a = 6, the initial number of books read
Let b = 2, the amount that the value grows by (doubles)
y+=+6%282%29%5Ex
x represents the number of years since age 6
At age 10, that is 10-6 years since age 6, or four years since age 6. So plug in 4 for x.
y+=+6%282%29%5E4
Now you want to simplify your answer.
y+=+6%2816%29
y+=+96
Joshua read a total of 96 books between ages 6 and 10.

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let +n+=+0+ when he was +6+ yrs old
+n+=+4+ when he was +10+ yrs old
Let +S+ = number of books he read
from age +6+ to age +10+
-----------------------------------------
+S+=+6%2A%28+2%5E%28+n%2B1+%29+-+1+%29+ and +n+=+4+
+S+=+6%2A%28+2%5E5+-+1+%29+
+S+=+6%2A%28+32+-+1+%29+
+S+=+6%2A31+
+s+=+186+
He read 186 books from age +6+ to age +10+
------------------------------------------------
check:
+S+=+6%2A2%5E0+%2B+6%2A2%5E1+%2B+6%2A2%5E2+%2B+6%2A2%5E3+%2B+6%2A2%5E4+
+S+=+6+%2B+6%2A2+%2B+6%2A4+%2B+6%2A8+%2B+6%2A16
+S+=+6+%2B+12+%2B+24+%2B+48+%2B+96+
+S+=+186+
OK

Answer by richwmiller(17219) About Me  (Show Source):
You can put this solution on YOUR website!
Lightning's answer is for how many books he read at age ten not from 6 to ten
6 12 24 48 96 

6  7  8  9 10