I would write the missing variable as x. It's what everyone uses.
Anyway, 91 divided by x is 65.
The way we can do this is reverse 65 and x.
91 divided by 65 = x.
91 divided by 1.4 = 65
65 x 1.4 = 91
x (or ?) = 1.4
Answer:
v ≈ 8.5 km/h
Step-by-step explanation:
Since the diameter of the wheel is 3 m the radius will be r = 1.5 m.
Use the radius of the water wheel to find it's circumference C:
[set r = 1.5 m]
⇒ 
⇒
m
One revolution of the water wheel corresponds to
meters so the angular velocity 15 rmp (revolutions per minute) corresponds to:
=
/min
Using this result, the speed of the river in kilometers per hour will be:
×
× 
⇒

⇒
≈
km/h
The 7 in 27,026 means 7,000. 7,000*10=70,000, so the answer is 70,000.
The area of a trapezoid can be found with the formula where b1 and b2 are the bases and h is the height. Let's plug in the values that we know and solve for h.
4 x 94 = 376
376 - 85 = 291
291 / 3 = 97