The average of 12 numbers is 75. The average of the first 5 numbers is 68. The average of the next 5 numbers is 20% more than the average of the first 5 numbers. The 11th number is 12 more than the 12th number. What is the average of the 11th and 12th numbers?

Given:Average of 12 numbers = 75Average of first 5 numbers = 68 Next 5 numbers are 20% more than first 511th number is 12 more than 12th number Formula Used:Sum = Average × Number of observations Solution:Sum of 12 numbers = 12 * 75 = 900 Sum of first 5 numbers = 5 x 68 340 Average of next 5 = 68+20% ×68 81.6 Sum of next 5 numbers = 5 * 81.6 = 408 Sum of first 10 numbers = 340 + 408 = 748 Sun of 11th and 12th = 900-748 152 Let 12th number x 11th number = x + 12x + (x + 12) = 1522x + 12 = 1522x = 140x = 7011th number = 82 Average = 70+82/2 =76 Final Answer:76