The sentence is correct in its present form, hence, no improvement is required.
The following expressions form a series followed by a (?). Find the odd one out first and then find that what will come in place of the question mark (?...
1 4 13 46 ? 976
...20, 30, 40, 55, ?, 160
4 6 12 ? 44 74
...104 156 234 ? 526.5 789.75
...25 34 61 106 169 ?
...32, 65 , 196, 785, ? , 23557
Choose the correct alternative
21: 3 ∷ 574: ?
1 1 8 4 27 9 ?
...97 106 121 138 157 180
...
