Answer:
I think it is
Step-by-step explanation:
(18.0, 22.0). We are 95% confident that the mean age of university students is between 18 and 22.
This is a mixture problem.
Let the 9 karat gold to be mixed be x. The 18 karat would weight (200 - x). Since the total = 200g.
mass1 * karat1 + mass2*karat = total mass * total carat
Let mass1 be x g. mass 2 would be = (200 -x)
karat 1 = 9 karat 2 = 18
Total mass = 200g.
Total karat = 14.
9*x + 18*(200 -x) = 14*200
9x + 18*200 - 18*x = 14*200
18*200 + 9x - 18x = 14*200
3600 - 9x = 2800
3600 - 2800 = 9x
800 = 9x
9x = 800
x = 800/9
x ≈ 88.89
Therefore 88.89 grams of 9 karat gold must be mixed.
Answer: A
Step-by-step explanation:
Using the equations y-3x=3 and x+y=31 you can find that x=7 and y=24. There for x is the smaller of the two numbers.
Answer:
No. of times Ellen draws a blue marble = 120
Step-by-step explanation:
No. of red marbles = 3
No. of blue marbles = 2
So, the required probability is 120.
