Answer:
4 minutes
Step-by-step explanation:
The value of 7k "minutes past nine" is the same as 8k" minutes to ten".
Since there are 60 minutes in an hour and 9 and 10 fall in between the same hour, this means that:
7k = 60 - 8k
7k + 8k = 60
15k = 60
k = 60 / 15
k = 4 minutes
That's the second one,
180 - x = r
Whenever two lines cross we get congruent opposite angles and supplemental adjacent angles, i.e. they add to 180 degrees.
The first one is almost right; we have r+y+z=180 and r+x=180 so x=y+z not quite what was written.
It would be 1/2 times 1/3 to get 1/6 cups of butter.
Total distance 5 km; at 5km / 0.65 h =
Second part distance: x; at 6 km/h, during t2
First part distance: 5 - x; at 8.75 km/h, during t1
V = d/t ⇒ t = d/V
t2 = x/6
t1=[5-x]/8.75
t2 + t1 = 0.65
x/6 + [5-x]/8.75 = 0.65
x/6 + 5/8.75 - x/8.75 = 13/20
x/6 - x/8.75 = 13/20 - 5/8.75
x/6 - 4x/35 =13/20 - 20/35
35x - 24x = (35*6)(35*13 - 20*20)/(20*35)
11 x = 16.5
x = 16.5/11 = 1.5 km
