Answer:
4.5 feet
Step-by-step explanation:
Here, we are concerned with calculating the actual height in feet of the door given the scale used in the maps drawing.
In the scale, scale to actual is 1 inch to 2.5 feet
let 1.8 inch scale = x actual feet
Thus mathematically, by cross multiplying; we have;
x = 2.5 * 1.8 = 4.5 feet
Answer:
20kg of 25% copper alloy
30kg of 60% copper alloy
Step-by-step explanation:
There are 2 kinds of metal, first metal(A) have 25% copper while the second metal(B) has 60% copper. The metalworker want to create 50kg of metal, which means the total weight of both metals is 50kg (A+B = 50). The metalworker also want the metal made of a 46% which is 23kg(0.25A + 0.6B = 0.46*50). From these sentences, we can derive 2 equations. We can solve this with substitution.
A+B = 50
A= 50-B
Let's put the first equation into the second.
0.25A + 0.6B = 0.46 *50
0.25(50-B) + 0.6B =23
12.5 - 0.25B + 0.6B =23
0.35B=23 -12.5
B= 10.5/ 0.35= 30
Then we can solve A
A= 50-B
A= 50-30
A=20
