The speed of wind and plane are 105 kmph and 15 kmph respectively.
<u>Solution:</u>
Given, it takes 6 hours for a plane to travel 720 km with a tail wind and 8 hours to make the return trip with a head wind.
We have to find the air speed of the plane and speed of the wind.
Now, let the speed wind be "a" and speed of aeroplane be "b"
And, we know that, distance = speed x time.

Now at head wind → 
So, solve (1) and (2) by addition
2a = 210
a = 105
substitute a value in (1) ⇒ 105 + b = 120
⇒ b = 120 – 105 ⇒ b = 15.
Here, relative speed of plane during tail wind is 120 kmph and during head wind is 90 kmph.
Hence, speed of wind and plane are 105 kmph and 15 kmph respectively.
Answer:
an average 7th grader owns 3 pairs of sneakers
<h2>
Answer:</h2>
The following which is not a requirement of a standard form of equation Ax+By=C is:
b) B ≥ 0
<h2>
Step-by-step explanation:</h2>
We know that the standard equation of a line is given by:

where A,B and C are integers and A is taken to be a non-negative integer i.e. (A≥0) also the greatest common factor of A,B and C is: 1.
Also A and B can't be both zero.
Hence, the correct option is:
Option: b
Answer: 15
Step-by-step explanation:
1/3x - 2 = 3
1/3x = 5
x = 15