Set up a system of equations.
0.10d + 0.25q = 39.25
d + q = 250
Where 'd' represents the number of dimes, and 'q' represents the number of quarters.
d + q = 250
Subtract 'q' to both sides:
d = -q + 250
Plug in '-q + 250' for 'd' in the 1st equation:
0.10(-q + 250) + 0.25q = 39.25
Distribute 0.10:
-0.10q + 25 + 0.25q = 39.25
Combine like terms:
0.15q + 25 = 39.25
Subtract 25 to both sides:
0.15q = 14.25
Divide 0.15 to both sides:
q = 95
Now plug this into any of the two equations to find 'd':
d + q = 250
d + 95 = 250
Subtract 95 to both sides:
d = 155
So there are 95 quarters and 155 dimes.
remember that a mode is a number repeated in the data set ( or the number list.
Mode: 6
we know that
A relationship between two variables, x, and y, represent a proportional variation if it can be expressed in the form y=kx
where
k is the constant of proportionality
Verify each table
table a
Let
x ----> distance
y ----> sound level
For each ordered pair calculate the value of k
k=y/x
so
(5,85) -----> k=85/5=17
(10,79) ----> k=79/10=7.9
the values of k are differents
that means
the table nor represent a proportional relationship
table b
let
x ----> volume
y ----> cost
k=y/x
(16,1.49) ----> k=1.49/16=0.093125
(20,1.59) ----> k=1.59/20=0.0795
the values of k are differents
that means
the table nor represent a proportional relationship
The minimum speed will be calculated as follows:
Time taken from Toledo to Elkhart=(8.15-5.45)=2 1/2 hours
Distance=136 miles
thus the speed between Toledo and Elkhart= 136 miles/2.5=54.4 mph
Distance between Toledo and Chicago is 244 miles
Distance between Elkhart and Chicago=244-136=108 miles
time taken to travel between Elkhart and Chicago assuming that I left Elkhart at exactly 8:15 and reach at 10.30:
=10:30-8:15=2.25 hours
thus the speed will be:
speed=(108)/(2.25)=48 mph
Thus for us to get to Chicago by 10:30 a.m we should drive at 48 mph
