Find out the missing term of the number series given below.

300, ?, 148, 221, 441, 1101.5

The correct option is 149.

To find the missing term of the number series, let us analyze the pattern between the consecutive numbers of the series: 300, ?, 148, 221, 441, 1101.5.

Let the terms of the series be represented as $T_1$, $T_2$, $T_3$, $T_4$, $T_5$, and $T_6$.

If we look at the terms after the missing term, we can determine the relationship between consecutive numbers:
For the fourth term ($T_4=221$) obtained from the third term ($T_3=148$):
$148\times 1.5-1=222-1=221$

For the fifth term ($T_5=441$) obtained from the fourth term ($T_4=221$):
$221\times 2.0-1=442-1=441$

For the sixth term ($T_6=1101.5$) obtained from the fifth term ($T_5=441$):
$441\times 2.5-1=1102.5-1=1101.5$

Thus, the general pattern is that each term is obtained by multiplying the previous term by a multiplier that increases by 0.5 at each step, and then subtracting 1:
$T_n=(T_{n-1}\times \text{multiplier})-1$

Applying this pattern from the beginning of the series:
First term ($T_1$) = 300
Second term ($T_2$) = $300\times 0.5-1=150-1=149$
Third term ($T_3$) = $149\times 1.0-1=149-1=148$

The calculation confirms that the missing term in the series is 149.