The given question is incomplete. The complete question is :
What volume of 0.160 M solution of KOH must be added to 550.0 mL of the acidic solution to completely neutralize all of the 0.150 M hydrochloric acid?
Answer: Volume in liters to three significant figures is 0.516 L
Explanation:
To calculate the volume of acid, we use the equation given by neutralization reaction:

where,
are the n-factor, molarity and volume of acid which is 
are the n-factor, molarity and volume of base which is KOH
We are given:

Putting values in above equation, we get:
(1L=1000ml)
Thus volume in liters to three significant figures is 0.516 L
Answer:
b = 56.67 m
Explanation:
It is given that,
Area of the triangular field is 255 m²
We need to find the base of the field if its height is 9 m.
The area of a triangle is given by :

So, the base of a triangle is 56.67 m.