Question
Average of 16 observations calculated by a student was
65 but when he again went through his observations he realised that he took value of three observations as 50, 59 and 40 in place of 90, 52 and 77 respectively and also realised that total observations taken by him was 15. Find the original average of all observations taken by him.Solution
Sum of 16 observations = 16 × 65 = 1040 Original average = {1040 + (90 + 52 + 77) - (50 + 59 + 40)}/15 = 1110/15 = 74
What will come in place of the question mark (?) in the following series?
1528, 1416, 1204, ?, 480, -32
143 Â Â Â Â 119Â Â Â Â 107Â Â Â Â 101Â Â Â Â Â 98Â Â Â Â ?
96 89 ? 90 94 91
...What value should come in the place of (?) in the following number series?
19, 235, 260, 324, 333, ?
What will come in place of the question mark (?) in the following series?
305...
In each of the following number series, one term is missing. Find the missing term.
3, 5, 20, 24, 144, 150, ?
1029, 1030, 1039, 1064, ?, 1194
75, 80, 95, ?, 155, 200
What will come in place of the question mark (?) in the following series?
1515, 184, ?, 455, 967, 624
7 29 61 ? 211 349
...