Answer:
15.

16. 10 ml of 20% saline and 40 ml of 10% saline
Step-by-step explanation:
A chemist takes x ml of 20% saline and y ml of 10% saline. In total, he takes
x + y ml that is 50 ml, so

There are
ml of salt in x ml of 20% saline and
ml of salt in 10% saline. There are
ml of salt in 50 ml of 12% saline. Thus,

15. We get the system of two equations:

16. Solve this system. From the first equation:

Substitute it into the second equation:

Answer:
option 4
Step-by-step explanation:


That's the beginning of Euler's number ' e '.
It falls between the square roots of 7 and 8 .
Hey ! You know what !
It falls between the square roots of any integer
less than 8 and any integer greater than 7 .
Answer:
267946.7
Step-by-step explanation:
here's the formula
V=4
/3πr3