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:
3 1/3 mph
Step-by-step explanation:
2.5 ÷ 0.75 = 3.3
or
5/2 ÷3/4 = 5/2 · 4/3 = 20/6 or 10/3 = 3 1/3
Answer:
26x-67-x²
Step-by-step explanation:
We are given
Expanding (x-8)²=x²-16x+64
10x-3-(x²-16x+64)
10x-3-x²+16x-64
26x-67-x²
Combine like terms ,
-4x+4y+10
There are 3 bracelets.
The first bracelet can occupy a position in 3 ways.
The second bracelet can occupy the remaining 2 positions in 2 ways.
The third bracelet can occupy the remaining position in 1 way.
The total number combinations is
3*2*1 = 6
Answer: 6
