Answer:
The percent price reduction was 15.83%
Step-by-step explanation:
we know that
In this problem
$379 represent the 100%
so
using proportion
Find out what percentage represent the difference between the original price and the final price
<span><span>2/5</span>−<span>1/4
</span></span><span>=<span><span>2/5</span>−<span>1/4
</span></span></span><span>=<span><span>2/5</span>+<span><span>−1/</span>4
</span></span></span><span>=<span><span>8/20</span>+<span><span>−5/</span>20
</span></span></span><span>=<span><span>8+<span>−5/</span></span>20
</span></span><span><span>=<span>3/20</span></span><span>(Decimal: 0.15)</span></span>
Answers:
- Total equation: x+y = 80
- Legs equation: 2x+4y = 248
- How many ducks? 36
- How many cows? 44
====================================================
Further explanation:
- x = number of ducks
- y = number of cows
x+y = 80 is the total equation (ie the head count equation) since we assume each animal has 1 head, and there are 80 heads total.
That equation can be solved to y = 80-x after subtracting x from both sides.
The legs equation is 2x+4y = 248 because...
- 2x = number of legs from all the ducks only
- 4y = number of legs from all the cows only
- 2x+4y = total number of legs from both types of animals combined
We're told there are 248 legs overall, so that's how we ended up with 2x+4y = 248
------------
Let's plug y = 80-x into the second equation and solve for x.
2x+4y = 248
2x+4( y ) = 248
2x+4( 80-x ) = 248
2x+320-4x = 248
-2x+320 = 248
-2x = 248-320
-2x = -72
x = -72/(-2)
x = 36
There are 36 ducks
Now use this x value to find y
y = 80-x
y = 80-36
y = 44
There are 44 cows.
------------
Check:
36 ducks + 44 cows = 80 animals total
36*2 + 44*4 = 72 + 176 = 248 legs total
The answers are confirmed.
