The average of twenty results is 62. If the average of first eleven results is 60 and that of the last ten results is 65 find the eleventh result.
Answers
Answer:
70
Step-by-step explanation:
Find the sum of the 20 results:
Average = 62
Sum = 62 x 20 = 1240
Find the sum of the first 11 results:
Average = 60
Sum = 60 x 11 = 660
Find the sum of the last 10 results:
Average = 65
Sum = 65 x 10 = 650
Find the 11th result:
Sum of the first 11 and last 10 = 660 + 650 = 1310
(Note that 1310 will have the 11th result added in twice)
11th result = 1310 - 1240 = 70
Answer: The 11th result is 70.
Answer:
70
Step-by-step explanation:
Given: Average of 20 results =62
Average of first 11 results = 60
Average of last 10 results =65
To find : The eleventh result
We know for Average
Sum of Numbers = Average of Numbers * Total numbers
For 20 Results: Sum = 62 * 20 = 1240
For First 11 Results: Sum= 60*11=660
For Last 10 Results: Sum=65 * 10=650
Total Sum of 11 and 10 Results= 650 + 660
= 1310
Now from the given statements we know that first eleven results and last 10 results contain the number 11 two times which means that the result 11 is added twice into the total sum of first and 10 results. If it was not added then we would get the sum equal to 1240 but it is added twice so
11th Result = Total Sum - Sum of 20 results
= 1310 - 1240
=70