Question
In a class of 60, where girls are twice that of boys,
Rohan ranked seventeenth from top. If there are 9 girls ahead of Rohan, how many boys are after him in rank?Solution
Sol: Let the number of boys be x. Then, number of girls = 2x ∴ x + 2x = 60 or x = 20 So, number of boys = 20 and number of girls = 40 Number of students behind Rohan in rank = 60 – 17 = 43 Number of girls ahead of Rohan in rank = 9 Number of girls behind Rohan in rank = 40 – 9 = 31 ∴ Number of boys behind Rohan in rank = 43 – 31 = 12
35 36 68 207 836 4205
...6 3.5 2.5 ? 8.5 23.75
...16, 54, 128, ‘?’, 432,686
7   24    43    66   ?      126
35    57    101    189    ?     717
130 114 106 102 100 ?
43Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â 44Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â 48Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â ...
If  2  4  6  x  14  28  30
Then, x³+ 2 x+1 = ?
17 ? 33 44 57 72
...35Â Â Â Â Â Â Â Â Â Â 36Â Â Â Â Â Â Â Â Â Â 40Â Â Â Â Â Â Â Â Â Â 49Â Â Â Â Â Â Â Â Â Â 65Â Â Â Â Â Â Â Â Â Â ?
...
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