Number- Acres

[Guest]

Thanks.

Two questions:

1) If 66 less posts were needed if they were placed 16 ft. apart instead of 12 ft. why is the 66 added to the 6W/16 instead of subtracting or added to the 6W/12 ?

2) If L = 2W, then W = .5L, could the problem be solved in the same way ?

[Guest]

6/12=1/2=4/4.......so....4/8-3/8=1/8....so.....w=66x8=528......sorry about earlier post

[Guest]

It's my 1 finger typing 1/2=4/8

[Guest]

1) The question states that 66 fewer posts are needed when placed 16 ft apart instead of 12 ft.
So the number of posts when placed 16 ft apart is 6W/16, the number when placed 12ft apart is 6W/12.
The number for 16ft apart is (or in other words equals) 66 less than the number for 12ft so
6W/16 = 6W/12-66
Equivalently we would need 66 more posts than the number for 16ft to get the number for 12 ft so
6W/16+66 = 6W/12
The two statements are equivalent, one rearranges to the other.

2) Yes, you can solve the problem using W = L/2, you should get the same answer.
The perimeter P = 2L+2W = 2L+2*L/2 = 2L+L = 3L, the statement about the number of posts becomes
3L/16+66 = 3L/12
9L/48+ 3168/48 = 12L/48
9L+3168 = 12L
3168 = 3L
1056 = L
and W = L/2 = 1056/2 = 528

How you substitute and eliminate variables doesn't matter you should always get the same answer in the end.

Hope this helped,

R. Baber.

[Guest]

Thanks - that helped again.