Answer:
.3
Step-by-step explanation:
A|B (A given b)= (A and b)/b
so
Sore throat|Fever= sore throatand fever/fever
.21/.7= .3
B is the answer
3. 122.025
4. 469.2
16.27/2 =8.135
8.135*15= 122.025
11.73 divided by 1/2= 23.46
23.46*20=469.2