A true-false question is to be posed to a husband and wife team. Both the husband and the wife will give the correct answer with probability 0.8. Which of the following is a better strategy for the couple? Strategy 1: choose one of them at random and ask the chosen person to answer the question Strategy 2: have them both answer the question. If their answers agree, give the common answer; if they disagree, flip a fair coin to determine which answer to given.

Choose either strategy both are equally successful

Step-by-step explanation:

Given:-

- The probability of success for both husband (H) and wife (W) are:

                              P ( W ) = 0.8 , P ( H ) = 0.8

Find:-

- Which of the following is a better strategy for the couple?

Solution:-

Strategy 1

- First note that P ( W ) & P ( H ) are independent from one another, i.e the probability of giving correct answer of husband does not influences that of wife's.

- This strategy poses an event such that either wife knows the answer and answer it correctly or the husband knows and answers in correctly.

- We will assume that probability of either the husband or wife knowing the answer is 0.5 and the two events of knowing and answering correctly are independent. So,

                           P ( Wk ) = P (Hk) = 0.5

- The event P(S1) is:

                           P(S1) = P ( Hk & H ) + P ( Wk & W )

                           P(S1) = 0.5*0.8 + 0.5*0.8

                           P(S1) = 0.8

- Hence, the probability of success for strategy 1 is = 0.8

Strategy 2

- Both agree , then the common answer is selected otherwise, one of their answers is chosen at random.

- The success of strategy 2, will occur when both agree and are correct, wife is correct and answers while husband is not or husband is correct and he answers.

- The event P(S2) is:

                   P(S2) = P ( H & W ) + P ( H / W' & Hk ) + P ( H' / W & Wk )

                   P(S2) = P ( H & W ) + P ( H / W') P ( Hk ) + P ( H' / W) P (Wk)

                   P(S2) = P ( H & W ) + P ( H / W')*0.5  + P ( H' / W)*0.5

                   P(S2) = 0.5* [ P ( H & W ) + P ( H / W') ]  + 0.5* [ P ( H' / W) + P ( H & W )]

                   P(S2) = 0.5*P(H) + 0.5*P(W)

                   P(S2) = 0.5*0.8 + 0.5*0.8

                   P(S2) = 0.8

- Hence, the probability of success for strategy 2 is = 0.8

Both strategy give us the same probability of success.

there are 70 more legs than eyes at the dog show (196 – 126 = 70). dogs have two more legs than eyes, and humans have the same number of legs as eyes. thus 70 is twice the number of dogs at the show, so the number of dogs is half of 70, which is 35. to get the number of humans, subtract 35 from 63: 63 – 35 = 28.

step-by-step explanation: