Question
Average of 17 numbers is 81. If the average of the first
six and last eight numbers is 91.5 and 71.5 respectively, and if the ninth number is 20% more than the eighth number and the tenth number is (50/9)% less than the ninth number, then find the ninth number.Solution
ATQ, Let the eighth number be 10x. So, the ninth number = 1.20 × 10x = 12x. Tenth number = 850/9 × 1/100 × 12x = 34x/3. So, 10x + 12x + 34x/3 = 81 × 17 – 6 × 91.5 – 8 × 71.5 = 255. Or, 100x/3 = 255. Or, x = 7.65. So, the ninth number = 12 × 7.65 = 91.8.
1, 1, 1.5, 3, 7.5 , ?
55 46 60 41 65 36 ?
800    544    416    352    ?     304
520Â Â 79Â Â 440Â Â 151Â Â Â 376Â Â Â ?
40 41 86 ? 1084 5445
...11Â Â Â 12.1Â Â Â Â 14.3Â Â Â Â 17.6Â Â Â Â Â 22Â Â Â Â Â ?
6Â Â Â Â Â Â Â Â Â Â 5Â Â Â Â Â Â Â Â Â Â 40Â Â Â Â Â Â Â Â Â Â Â 32Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â 249Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â 240
2Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â 4Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â 5Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â 19Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â 70...
130 114 106 102 100 ?
The series given below contains a sequence of numbers. Accordingly identify the incorrect number.
85, 84, 81, 88, 77, 92, 72
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