Answer:
We must add 400 ml of water.
Step-by-step explanation:
We can use the following equation:

Where:
- C(i) is the initial concentration of the solution (80%)
- C(f) is the final concentration of the solution (30%)
- V(i) is the initial volume (150 ml)
- V(f) is the final volume
Now, we just need to solve the equation for V(f).



Therefore, we must add 400 ml of water.
I hope it helps you!
Most of the information's required for solving the question is already given in the question.
Height of the building that casts a shadow of 20 m = 32 m
Then
Height of the man that casts a shadow of 1.2 m = (32/20) * 1.2 meter
= 3.2 * 1.2 meter
= 3.84 meter
So the actual height of the person casting a shadow of 1.2 meter is 3.84 meters. I hope that the procedure used for solving the problem is easy enough for you to understand. You can definitely use this method in future for solving problems of similar type without requiring any additional help from outside.
Answer:
3
Step-by-step explanation:
Parallel lines have equal slopes, thus
line AB is parallel to line CD