Answer:
No. of pages he read by the end of the 8th day = 425
Step-by-step explanation:
Charlie started from page 1 and read the same number of pages each day. Suppose x is the number of pages he read each day, the last page he read on the first day would be:
<u>Last page for day 1 = 1 + x</u>
This would be the first number he noted on the list.
The second page number can be determined by adding the number of pages he read to the last page for day 1.
Last page for day 2 = 1 + x + x
= 1 + 2x
Similarly, the last page he read on the third day is:
Last page for day 3 = 1 + 3x. Similarly,
Last page for day 4 = 1 + 4x
Last page for day 5 = 1 + 5x
Last page for day 6 = 1 + 6x
Last page for day 7 = 1 + 7x
Last page for day 8 = 1 + 8x
His Mom added all of the page numbers and got a total of 432. So,
432 = 1+x + 1+2x + 1+3x + 1+4x + 1+5x + 1+6x + 1+7x + 1+8x
432 = 8 + 8x
8x = 432-8
8x = 424
x = 424/8
x = 53
By the end of the 8th day he actually read 1 + 8x pages. Substituting the value of x in this expression, we get:
No. of pages he read by the end of the 8th day = 1 + 8(53)
= 1 + 424
No. of pages he read by the end of the 8th day = 425
since it is exactly in the halfway between 
