Answer:
c This is the direct variation
Step-by-step explanation:
The equation for direct variation is y= kx
Solving this for k
y/x =k
So y/x must be a constant
a. 9/3 =3
2/7 does not =3 so this is not a direct variation
b 1/2 = .5
-3/6 = -.5
This is not the same so this is not a direct variation
c. 27/9 =3
18/6 =3
9/3 =3
This is a direct variation with a constant of 3
d 5/-7 = -5/7
1/-3 = -1/3
This is not the same so this is not a direct variation
Answer:
(a) How many grams of copper are in the resulting mixture?
= 160 grams
(b) What percentage of the resulting mixture is copper?
= 61.5%
Step-by-step explanation:
(a) How many grams of copper are in the resulting mixture?
From the question: Suppose that a certain alloy is made by mixing 70 grams of an alloy that contains 12% copper with 90 grams of pure copper.
The number of grams of copper in the resulting mixture = 70 grams + 90 grams = 160 grams
(b) What percentage of the resulting mixture is copper?
70 grams of an alloy that contains 12% copper = 70 × 12%
= 70 grams × 0.12
= 8.4 grams
The number of grams of copper in the resulting mixture = 160 grams
The percentage of the resulting mixture that is copper is
=( 8.4 grams + 90 grams of pure copper/160) × 100
= 98.4/160 × 100
= 61.5%
If Kenny bought 20 packs of baseball cards and there are 12 cards in a pack, you can calculate how many cards did Kenny buy using the following steps:
20 packs of cards * 12 cards in a pack = 20 * 12 = 240 cards
Result: Kenny bought 240 cards.
The nearest tenth (243.9)
The nearest hundredth (243.88)
The nearest ten (240)
The nearest hundred (200)