the gender of the kids does not matter so it can be discarded.
you add up how many boys and girls in the class to make a total of 50 kids
your 100% is 50
meaning 40% of 50 is 20
so if 20 kids took the bus to school then 30 did not take the bus.
Answer:
Step-by-step explanation: <u>Speed</u> is distance an object travelled per unit time.
It is represented by letter v and can assume various units.
1) 

v = 18 miles per hour
Her average speed is 18 mph.
2) Rearraging formula for distance:
d = v.t
d = 70 * 4
d = 280 miles
You would travel 280 miles.
3) 

v = 52.5 mph
My average speed is 52.5 mph.
4) Rearranging formula to determine time:


t = 2.34 hours
It will take 2 hours and half to arrive in Leeds. So, we will be expected to arrive at 12:04.
5) The unit change but the way of calculating time is the same.

t = 500 s
or t = 8.34 minutes
It will take, for an athlete to run 2000m, 8.34 minutes.
6) a) All units must match, so for a speed in mph:
45 minutes is 0.75 hours. Total time is 8.75 hours.

v = 560 mph
The average speed is 560 mph.
b) 

t = 6.67 hours
Sam will take 6.67 hours to covered the distance.
The absolute value parent function.
M<ABC = m<EBD = 36 (vertical angles)
78 - x + 36 + 3x - 10 = 180 (straight angle)
Now solve for x
78 - x + 36 + 3x - 10 = 180
2x + 68 = 180
- 68 -68 (subtract 68 on both sides)
2x = 58
x = 29