Question : The average of twelve numbers is 39. The average of the last five numbers is 35, and that of the first four numbers is 40. The fifth number is 6 less than the sixth number and 5 more than the seventh number. The average of the fifth and sixth numbers is:

Option 1: 47

Option 2: 39

Option 3: 44

Option 4: 50

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

Question : A's salary is 35% more than B's salary. How much percent is B's salary less than that of A's? (correct to the nearest integer)

Option 1: 17.5%

Option 2: 20%

Option 3: 35%

Option 4: 26%

Question : The average of ten numbers is 72. The average of the first four numbers is 69 and that of the next three numbers is 74. The 8th number is 6 more than the 9th number and 12 more than the 10th number. What is the average of the 8th and 9th numbers?

Option 1: 76

Option 2: 76.5

Option 3: 77

Option 4: 77.5

Question : A boy added all-natural numbers from 1 to 20. However, he added one number twice, due to which the sum became 215. What is the number which he added twice?

Option 1: 5

Option 2: 7

Option 3: 11

Option 4: 15