Answer:
Ming must add 0.375 L of a 10% sugar solution
Step-by-step explanation:
if 3 L = 80%
1.5 L should = 40% (since it is half of 80%)
and if 40 divided by 4 = 10%
1.5 also needs to be divided by 4
so 1.5 divided by 4 = 0.375
that means Ming must add 0.375 L of a 10% sugar solution
Answer:
45 minutes
Step-by-step explanation:
At 30 mph for 1/4 hour, Peter has a 7.5 mile head start. After he leaves, Mitchell closes that gap at the rate of 40-30 = 10 miles per hour. It will take him ...
t = d/s
t = (7.5 mi)/(10 mi/h) = 0.75 h
to catch Peter.
Mitchell will catch Peter in 45 minutes.
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<em>Alternate Solution</em>
Another way to look at it is that Mitchell's 10 mph advantage is 1/3 of Peter's speed, so it will take 1/(1/3) = 3 times the period of Peter's head start:
3 × 15 minutes = 45 minutes . . . for Mitchell to catch Peter
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You can write equations involving time and distance and see where the distances traveled become the same. You need to be careful choosing the time reference, since you're concerned with Mitchell's travel time. I personally prefer to work "head start" problems by considering the differences in time and speed, as above. This is where you end up using the equations approach, anyway.
The number of stamps with penny in terms of x is 
<em><u>Solution:</u></em>
Given that,
Ryan has x stamps in his collection
Number of stamps of Ryan = x stamps
Let the stamps with penny be "a"
Ryan has 6 times as many stamps as penny
Therefore,
Number of stamps in Ryan = 6 times as many stamps as penny
Thus number of stamps with penny in terms of x is
Answer:
The answer is C
Step-by-step explanation:
So,
We'll just use A to represent both Jan and Mya's miles, since they ran the same number.
We have the equations:
1. Jan (J) = Mya (M)
2. Sara (S) = M - 8
3. 2A + S = 64
J = M
S = M - 8
We'll just use A to represent both J and M.
S = M - 8
We'll use Elimination by Substitution.
2A + A - 8 = 64
Collect Like Terms
3A - 8 = 64
Add 8 to both sides
3A = 72
Divide both sides by 3
A = 24
Since
A = J
and
A = M
and
J = M
then
J = 24
M = 24
Substitute
S = 24 - 8
S = 16
Check
24 + 24 + 16 = 64
64 = 64 This checks.
So,
J = 24
M = 24
S = 16
