In order to determine the correct answer, it would be helpful to set up equations. We do as follows:
Let x = students
y = adults
x + y = 215
.50x + 2y = 250
SOlving simultaneously, we have:
x = 120 students
y = 95 adults
Hope this answers the question. Have a nice day.
Answer:
19 coins
Step-by-step explanation:
We know that mean is the sum of all the elements divided by the number of elements there are: m = t/n, where m is the mean, t is the total sum, and n is the number of elements.
Here, we are given the mean number of coins for all 27 + 18 = 45 children is 16, so m = 16 and n = 45. Then:
m = t/n
16 = t/45
t = 720
This t means that the total number of coins that all the boys and girls have is 720 coins.
Now, we also know the mean number of coins for the boys only, which is 14. Since there are 27 boys, then:
m = t/n
14 = t/27
t = 378
This t means the total number of coins all the boys have.
Subtracting 378 from 720, we get 342, which is the total number of coins the girls have. We also know there are 18 girls, so:
m = t/n
m = 342 / 18 = 19
Thus, the mean is 19 coins.
If you set you the equations such as 3c+5w=23 and 6c+2w=20 and then solve the first equation for c, you get c= (23-5w)/3 Taking that equation and substituting it for 'c' in the second equation (so the second equation becomes: 6((23-5w)/3)+2w=20 ) you get w=3.25 If you plug that back into your first equation (so it now becomes: 3c+5(3.25)=23 ) you get c=2.25 So the answer would be walnuts cost $3.25 per lb and choc. chips cost $2.25 per lb.
<h3>Rate of the boat in still water is 70 km/hr and rate of the current is 15 km/hr</h3><h3><u>Solution:</u></h3>
Given that,
A motorboat travels 165 kilometers in 3 hours going upstream and 510 kilometers in 6 hours going downstream
Therefore,
Upstream distance = 165 km
Upstream time = 3 hours
<h3><u>Find upstream speed:</u></h3>
Thus upstream speed is 55 km per hour
Downstream distance = 510 km
Downstream time = 6 hours
<h3><u>Find downstream speed:</u></h3>
Thus downstream speed is 85 km per hour
<em><u>If the speed of a boat in still water is u km/hr and the speed of the stream is v km/hr, then</u></em>
Speed downstream = u + v km/hr
Speed upstream = u - v km/hr
Therefore,
u + v = 85 ----- eqn 1
u - v = 55 ----- eqn 2
Solve both
Add them
u + v + u - v = 85 + 55
2u = 140
u = 70
<em><u>Substitute u = 70 in eqn 1</u></em>
70 + v = 85
v = 85 - 70
v = 15
Thus rate of the boat in still water is 70 km/hr and rate of the current is 15 km/hr
Not an answer, but we need the info on the table...
