A medicine is known to be 50% effective to cure a patient. If the medicine is given to 4 patients, what is the probability that at least one patient is cured by this medicine
1. 1/2
2. 1/16
3. 3/4
4. 15/16
1. 1/2
2. 1/16
3. 3/4
4. 15/16
Correct Answer – Option 4 : 15/16
Concept:
Probability of event hapening = 1 – probability of event not happening
Calculation:
Here, probability of medicine to cure patient = 1/2
And, probability of none cured = 1 – 1/2 = 1/2
The probability that at least one patient is cured by this medicine = 1 – none patient cured by this medicine
= 1 – (1/2) ×(1/2) ×(1/2) ×(1/2)
= 1 – (1/2)4
= 15/16
Hence, option (4) is correct.