Answer:
<em>The metalworker should use 60 kg of metal alloy that is 70% copper and 40 kg of metal alloy that is 20% copper.</em>
Step-by-step explanation:
<u>System of Equations
</u>
Let's call
x=amount of metal alloy that is 20% copper
y=amount of metal alloy that is 70% copper
The metalworker wants to create 100 Kg of 50% copper alloy. This gives us the first relation
x+y=100
The combination of 20% of x and 70% of y will produce 50% of the sum of both, thus
20x+70y=50(x+y)
Operating
20x+70y=50x+50y
Reducing and dividing by 10
2y=3x
The system of equations is easily solved by isolating x in the first equation
x=100-y
And replacing into the last equation
2y=3(100-y)
Operating
2y=300-3y
5y=300
y=60
Thus
x=100-60=40
The metalworker should use 60 kg of metal alloy that is 70% copper and 40 kg of metal alloy that is 20% copper.
Imani's time=4 times carissa's time
=28 min
there fore, i=4*c=28
c=i/4;=>28 divided by 4 which is 7 min
If the amount she saved was $6 for 20%, then the formula for finding savings would be cost*percentage.
But if you want to find the original cost, then you play with the current formula until you get this. $6/20%. Have a good one :)
Answer:24r+48h= $1248
Step-by-step explanation:
24*36+48*8
864 + 384 = 1248
Not sure if it's correct I'm not brilliant with equations xx
Answer:
34 rolls
Step-by-step explanation:
For Frank to cover his whole ceiling, he needs paper that will cover
20 ft x 20 ft
20 x 20 = 400 ft
So, Frank needs to cover 400 ft of the ceiling. He has to split up this large need for paper into smaller rolls, because the rolls he can buy are small.
If each roll has 12 ft, we need to find how many 12-feet are in 400 feet.
To do this, we should divide
400 / 12
= 33.333
Because Frank cannot cover the whole ceiling using only 33 rolls, he has to buy an additional roll to make sure he can cover the extra area [that would be left over if he were to only buy 33 rolls, which would only cover 396 feet]
So, Frank will need to buy 34 rolls to have enough paper to entirely cover his ceiling.
