Missing number in the series 9, , 6561, 43046721 is: 81 25 62 31 18 9. one number is 2 more than 3 times another. their sum is 22. find the numbers. 8, 14 5, 17 2, 20 4, 18 10, 12 10. the missing number in the series 1, 4, 27,, 3125 is: 81 35 729 256 115 11. the next number in the series 3, 4, 6, 7, 9, 10 is: 12 11 15 17 13 12. a farmer is planting a straight row of crops with 3 feet between each plant. if 23 are planted, what is the distance between the first and last plant? 72 66 69 63 75