Answer:
15:1
Explanation:
When a coin is tossed once, there are two probable outcome: a heads or a tail.
Now, when the coin is tossed four times, the total number of outcomes will be:
![2^4=16](https://img.qammunity.org/2023/formulas/mathematics/college/v7kgvuk1od32ur1pplq6nkentvgyxpsyex.png)
• The outcome of obtaining ,heads all 4 times ,= 1
,
• The number ofunfavourable outcomes = 16-1 = 15
The odds against an event is calculated using the formula below.
![\frac{\text{Number of Unfavourable Outcomes}}{\text{Number of favourable Outcomes}}=(15)/(1)=15\colon1](https://img.qammunity.org/2023/formulas/mathematics/college/uxsce1ataw2hs88puzlhc0p0v7cg1k0v9w.png)
The odds against obtaining heads all 4 times is 15:1.