Speed of the boat = u
speed of the current = v
in downstream,
u - v = 105/5
u - v = 21
in upstream
u + v = 105/7
u + v = 15
add both equations
2u = 36
u = 18
v = -3
so
speed of the boat = 18 km/h
speed of the current = 3 km/h
<h3>One less than the product of four and a number is 11. What is that number ?</h3>
Answer: The number is 3
Step-by-step explanation:
We will call X the number, then 4X - 1 = 11
4X = 11 + 1 =12
X = 12/4 =3
This is the number = 3
Let the width of room be =x mtrs
Then the length is x+2 mtrs
As Perimeter = 2(l+b) = 2(x+x+2)
16 = 2 ( 2x+2)
16/2 = 2x +2
8=2x+2
2x= 8-2 = 6
x = 6/2 =3 mtrs
Therefore width of the room is 3 mtrs