Question : The average of 25 results is 20. The average of the first 12 results is 15 and that of the last 12 results is 18. Then the 13th result is:

Option 1: 100

Option 2: 101

Option 3: 104

Option 4: 103

Question : The average of 25 results is 20. The average of the first 12 results is 15 and that of the last 12 results is 18. Then, the 13^th result is: 

Option 1: 100

Option 2: 101

Option 3: 104

Option 4: 103

Question : Arrange the given ratios in descending order
15 : 7, 5 : 11, and 21 : 77.

Option 1: 21 : 77 > 5 : 11 > 15 : 7

Option 2: 15 : 7 > 5 : 11 > 21 : 77

Option 3: 15 : 7 > 21 : 77 > 5 : 11

Option 4: 5 : 11 > 15 : 7 > 21 : 77

Question : The average of some natural numbers is 15. If 30 is added to the first number and 5 is subtracted from the last number, the new average becomes 17.5. What is the total number of natural numbers?

Option 1: 15

Option 2: 30

Option 3: 20

Option 4: 10

Question : The average of 19 numbers is 22.8. The average of the first ten numbers is 18.4 and that of the last ten numbers is 28.6. If the $10^{\text {th}}$ number is excluded from the given numbers, then what is the average of the remaining numbers? (Your answer should be nearest to an integer.)

Option 1: 21

Option 2: 23

Option 3: 22

Option 4: 20