The interviewer says, “Assume that it is not necessary for you to travel to this distant clinic and wait for the laboratory result, if the card test is available to your local health centre. The time cost and travelling cost are sure to be saved. Also, the card has more than 90% accuracy to detect correctly if malaria is present.

“If so, would you like to pay $ 5.0 for test.

Option 1 YES: If yes, would you like to pay $7.0

If yes, would you like to pay $ 9.0

Option 2 NO: If no, would you like to pay $3.0

If no, would you like to pay $ 1.0”

In binary valuation questions, the respondent only accepts or rejects one bid.