Question

http://screencast.com/t/eNZQhh1pC0C

Answer 1

@Vincent-Lyon.Fr

Answer 2

Number of beats per second between f1 and f2 is |f2-f1|.
The rest should be ok for you.

Answer 3

Yes I know that. But how do I relate the first and last?

Answer 4

When you have found the answer, you will see that one of the tuning fork plays an A.

Answer 5

Simply add-up the number of beats from the first to the last.

Answer 6

let f1 is f
then f56 is 3f
|fi-f56| = 55x4

i think now you can find the answere

Answer 7

x2-x1=4
x3-x2=4
x4-x3=4
.
.
.
xn-xn-1=4

3x1-x1=4
3x1-x1=4*56
2x1=4*56
x1=2*56?

Answer 8

@Deepakrathee is right.
@AravindG counted one interval too many ;-)

Answer 9

it will be 2x55

Answer 10

@Vincent-Lyon.Fr I think I made a mistake somewhere?

Answer 11

Yeah right :) 55 I see! Thanks!