Answer:
The speed of the boat is 20 km/hr
Step-by-step explanation:
Let s be the speed of boat in still water
Let d be the distance
Upstream speed = s-4
Jane took 30 min to drive her boat upstream to water-ski at her favorite spot.
So, Distance traveled in upstream =
Downstream speed = s+4
So, Distance traveled in downstream = 
So, 
30s-120=20s+80
10s=200
s=20
Hence The speed of the boat is 20 km/hr
Answer:
y = x + 5: x=y−5
2x + y = 17
: x=-1/2y+17/2
Step-by-step explanation:
I do not exactly know what you were asking but I just answered the questions, if that is not what you were looking for tell me so I can try and edit my answer
Answer:
it most likely 3 1/2 or 7/2
Step-by-step explanation:
Area of trapezium = 1/2(a+b)h
= 1/2(10+24)12
= 1/2×34×12
= 204 square units