Answer:
64 km/hr
Step-by-step explanation:
216 - 56 = 160 km on good road
216km / 48 km/hr = 4.5 hours total time
56 km / 28 km/hr = 2 hours on bad road
then 2.5 hours on good road ( for total 4.5 hrs)
160 km / 2.5 hr = 64 km/hr on the good road portion
Answer:
Step-by-step explanation:
hope this helps! <3
Answer for problem 46 is choice A
Answer for problem 47 is choice B
Answer for problem 48 is choice E
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Work Shown
Problem 46
Equation 1: 3x+y = 17
Equation 2: x+3y = -1
Add equation 1 to equation 2 to get 4x+4y = 16. Divide every term by 4 to get x+y = 4. Then finally multiply both sides by 3 to get 3x+3y = 12
That shows why the answer is choice A
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Problem 47)
If y hours pass by, then y-(2/3)y=y/3 is the time value (2/3)y hours ago
So,
Distance = rate*time
d = r*t
d = x*(y/3)
d = (xy)/3
That's why the answer is choice B
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Problem 48)
Let L1,L2,L3 be the three lists where
L1 = {a1,a2,a3,...,ak} there are k scores here
L2 = {a1,a2,...,a10} there are 10 scores here
L3 = {a11,a12,...,ak} the remaining k-10 scores
S(L1) = sum of the scores in list L1
M(L1) = mean of L1 = 20 = S(L1)/k
M(L2) = mean of L2 = 15 = S(L2)/10
S(L1) = 20k
S(L2) = 150
S(L1) = S(L2)+S(L3)
M(L1) = [S(L2)+S(L3)]/k
20 = [150+S(L3)]/k
20k = 150+S(L3)
S(L3) = 20k-150
M(L3) = [S(L3)]/(k-10)
M(L3) = (20k-150)/(k-10)
So that shows why the answer is choice E
The x represents how many songs Sabrina has because if you are saying Nicolas has three less than twice as many as her then you are doubling the amount of songs Sabrina has and you're subtracting 3 from that to get how many songs Nicolas has. Let's say Sabrina has 29 songs. Now we are trying to find out how many songs Nicolas has. 2x-3. 2(29) - 3. 58-3. Nicolas has 55 songs if Sabrina were to have 29. I really hope this helped :)
