Answer:
Average speed = 9.91 m/s
Explanation :
Total distance covered by a runner = 200 m
Time taken to complete this distance = 20.19 sec
We need to find the average of runner speed in meter/sec
We use the speed, distance, time formula

speed = 
Average speed = 9.91 m/s
that's the final answer.
I hope it will help you.
Answer:
The simplified expression is: 12(7m - 6n)
Step-by-step explanation:
Greatest common factor between 84 and 72
We keep dividing 84 and 72, while they can be divided by the same factor. So
84 - 72| 2
42 - 36|2
21 - 18|3
7 - 6
So the greatest common factor is 2*2*3 = 12.
Rewrite 84m - 72n as a product of two factors
Evidencing 12

Answer:
25°
Step-by-step explanation:
ACE + BCE = 180
Since sum of angles on a straight line equals 180°
(2x+2)+(5x+3)=180
7x+5=180
7x=175
x= 25°
Silver = 10%
Gold = 90%
Amount of gold to be deducted
90/100 × 18 = 16.2 g
75/100 × 18 = 13.5
16.2 - 13.5 = 2.7
Amount o silver to added.
2.7 × 5 = 13.5
Answer = 13.5 g