Let us say that:
a = ones
b = fives
c = twenties
So that the total money is:
1 * a + 5 * b + 20 * c = 229
=> a + 5b + 20c = 229 -->
eqtn 1
We are also given that:
c = a – 5 -->
eqtn 2
a + b + c = 30 -->
eqtn 3
Rewriting eqtn 3 in terms of b:
b = 30 – a – c
Plugging in eqtn 2 into this:
b = 30 – a – (a – 5)
b = 35 – 2a -->
eqtn 4
Plugging in eqtn 2 and 4 into eqtn 1:
a + 5(35 – 2a) + 20(a – 5) = 229
a + 175 – 10a + 20a – 100 = 229
11a = 154
a = 14
So,
b = 35 – 2a = 7
c = a – 5 = 9
Therefore there are 14 ones, 7 fives, and 9 twenties.
500 + 30g <span>≤ 8000
30g </span><span>≤ 7500
g </span><span>≤ 250</span>
Answer:
Step-by-step explanation:
To answer this problem, we must bear in mind that the express train travels 3 times faster than the freight train.
If we call F the distance that the freight train travels and we call E at the distance that the express train travels, we must have the distance between them after 15 minutes it must be 30 miles.
So
We also know that:
Since the express train travels 3 times faster than the freight train.
So, like both equations, we have to:
Then 
miles in the opposite direction.
This is the distance you traveled in 15 minutes.
Therefore, the speed of the express train (
) is the distance traveled between the time it did
Answer:
5 felt pads.
7 cards.
Step-by-step explanation:
Remark
- The total number of items is 12
- So let the felt sheets be x
- Let the cards = y
Equations and Solution
x + y = 12
Now the price is 7.75 that she has to pay for the 12 items. She wants to come back with 0 dollars.
0.5x + 0.75y = 7.75 Multiply this equation by 2
x + 1.5y = 15.50 write the first equation underneath and subtract.
<u>x + y = 12</u>
.5y = 3 Divide by 0.5
y = 3/0.5
y = 7
So she can get 7 cards.
x + y = 12
x + 7 = 12
x = 12 - 7
x = 5
So she can buy 5 felt pads.
