Answer:
Speed of river's current = 5 mph
Step-by-step explanation:
Let 'd' be the distance covered
Let x be the speed of the rivers current
Speed upstream = 15-x
speed downstream = 15+x
Time = distance / speed
time upstream = 
time downstream = 
the ferry trip upstream takes twice as long as its return trip downstream
= 
divide both sides by d
= 
cross multiply


Add 2x on both sideds

subtract 15 from both sides and divide by 3

x=5
Speed of river's current = 5 mph
Answer:
The diameter is related because it helps find the circumference.
Answer: 55
Step-by-step explanation: There is one simple theorem we need to know in order to solve for this.
Triangle Angle-Sum Property: All three angles interior angles of a triangle add up to 180°.
Thus, we could label the points A, B, and C, and set up an algebraic expression.
Let A = 27, B = 98, and C = x.
A + B + C = 180°.
Substituting A, B, and C we get:
27 + 98 + x = 180°.
Adding, we get:
125 + x = 180°
Subtracting 125 by 180, we get:
x = 55°
Thus, the angle X is 55°.
We could have simply solved this by just doing 180 - 98 - 27 = 55 in the first place, but I wanted to show you how I got such results.
The answer is 0.154 m
Step 1. Calculate the volume of gasoline tank (V) using the known mass (m) and density of gasoline (D).
D = m/V
⇒ V = m/D
D = 719.7 kg/m³
m = 45.0 kg
V = 45.0 kg/719.7 kg/m³ = 0.0625 m³
Step 2. Calculate the depth of the tank (d) using the known volume (V) of gasoline and width (w) and length (l) of the tank:
V = d * w * l
0.0625 = d * 0.900 * 0.450
0.0625 = d * 0.405
d = 0.0625 / 0.405
d = 0.154 m