Chapter 11.8, Problem 17WE

(a)

To determine

To Find: The probability that the part of the bird call was erased.

Answer to Problem 17WE

  $\frac{13}{50}$

Explanation of Solution

Given: A researcher was tape recording birdcalls. The tape recorder had a one hour tape in it. Eight minutes after the recorder was turned on, a $5\min$ birdcall began. Unfortunately the researcher accidently erased $10\min$ of the tape.

  

Duration of the recording for the first bird call.

  $8+5=13\min$

Since the $60\min$ tape, $10\min$ of the tape was erased

Thus remaining time = $50\min$

Therefore

Probability $=\frac{13}{50}$

(b)

To determine

To Find: The probability that all of the bird call was erased.

Answer to Problem 17WE

  $\frac{5}{50}$

Explanation of Solution

Given: A researcher was tape recording birdcalls. The tape recorder had a one hour tape in it. Eight minutes after the recorder was turned on, a $5\min$ birdcall began. Unfortunately the researcher accidently erased $10\min$ of the tape.

For all the bird call, the $5\min$ bird call must be completely erased when $10\min$ minutes erased.

So the probability that all of the bird call was erased.

  $P=\frac{5}{50}$