Which number should replace ‘?’ in the following series? 240, 120,? , 180, 360, 900

What should come in place of question mark (?) in the following number series? 132 156 ? 210 240 272

Which number is unsuitable in the following series? 5, 3, 6, 10, 9, 12, 17, 15, 18, 23

What should come in place of ? in the following series ? 117, 98, 80, 64, ?, 42

What will be the next number in the following number series? 48, 24, 72, 36, 108, ?

Find the missing number in the following number series. 3, 5, 8, 10, ?, 15, 18, 20