Average of 100 numbers in 5 Seconds #mathstricks

The average of 100 numbers is 44 .The average of these 100 numbers and four other new numbers is 50. The average of the four new numbers will be

If a sprinter runs a distance of 100 metres in 9.83 seconds, calculate his average speed in km/h.

The average of 10 numbers is 41. The average of first 3 numbers is 39.4 and the average of last 4 numbers is 43.5. 4^(th) number is 2 more than the 5^(th) number and 0.2 more than the 6^(th) number. What is the average of the 4^(th) and 6^(th) numbers

The average of 9 numbers is 11. If each of these 9 numbers is multiplied by 5 and then 5 is added to each of these resultant numbers, then the new average is :

The average of 41 numbers is 63. The average of first 21 number is 61.5 and that of last 21 numbers is 65.5. if 21^(St) number is excluded then the average of remaining numbers is: