Answer:
95%
Step-by-step explanation:
Let the proportion who can swim be denoted by P(S) while the proportion that can whistle be denoted by P(W)
The proportion that can swim and whistle will be P(S and W)
The proportion that can swim or whistle will be P(S or W)
To get the proportion that can swim or whistle will be P(S or W), we use
P(S or W)=P(S)+P(W)-P(S and W)
Given that P(W) is 70%, P(S) is 80% and P(S andW) is 55% then
P(S or W)=80%+70%-55%=95%
