Answer :
Answer:
No of patients having longsightedness = 5
No of patient having shortsightedness = 7
Patients requiring varifocal lenses will be =12
Step-by-step explanation:
Total no of patients = 16
As
No of patients having neither long nor shortsightedness = 4
Let
No of patients having longsightedness = x
So
No of patient having shortsightedness = [tex]x+2[/tex]
Equation becomes
[tex]x+(x+2)+4= 16\\2x+6 = 16\\2x= 16-6\\2x= 10\\x= \frac{10}{2} \\x= 5[/tex]
Now
No of patients having longsightedness = x= 5
No of patient having shortsightedness = [tex]x+2[/tex] =[tex]5+2[/tex]
= 7
Patients requiring varifocal lenses will be = 5+7
= 12