Answer: 15
Step-by-step explanation:
Average is sum of scores/ number of scores, from the question, average is given as 15.
Let the missing score be x
Equation for the questionis represented as: 12 + 18 + x /3 = 15
30 + x /3 = 15
Cross multiply
30 + x = 15×3
30 + x = 45
Subtract 30 from both sides
30 + x -30 = 45 -30
x = 15.
Check:
12 + 18 + 15/3 = 15
45/3 = 15
I hope this is clear, please mark as brainliest answer
On the graph, it shows that the shortest meeting has lasted for 1/4 of an hour. An hour has 60 mins, you know it the shortest will be 15 minutes.
If its for any other number that you do not know, you can list as a proportion:
1/4 = x/60 (1 and x are on the top of the fractions)
Cross multiply: 1 * 60 = 60
Then divide by the number on the opposite corner of x: 60/4
x = 15
(a-b)(a+b) because when you reverse the sum you do axa and ax-b xx