Chapter 13, Problem 42SGR

To determine

Calculate probability of P (white, then white) without replacement.

Answer to Problem 42SGR

Probability of finding white and then white marker without replacement is $\frac{10}{153}$ .

Explanation of Solution

Given:

No. of red marker=8

No. of green marker=5

No. of white marker = 5

Calculations:

Here, we have to calculate probability of finding blue white and again white marker in a box without any replacement.

Total number of markers =8+5+5=18

Probability of finding first white marker is,

  $P(firstwhite)=\frac{No.ofwhitemar\ker }{Totalno.ofmar\ker }=\frac{5}{18}$

Probability of finding second white marker is,

  $P(\sec ondwhite)=\frac{No.ofwhitemar\ker afterremovingonewhitemar\ker }{Totalno.ofmar\ker afterremovingonewhitemar\ker }=\frac{4}{17}$

Probability of finding white and again white marker is,

  $\begin{array}{l}P(whiteandthenwhite)=P(firstwhite)\times P(\sec ondwhite)\\ =\frac{5}{18}\times \frac{4}{17}\\ =\frac{20}{306}\\ =\frac{10}{153}\end{array}$

Conclusion:

Therefore, we are able to calculate probability of finding white and then white marker in a box.