Question 140
Select the number from the given options that can replace the question mark (?) in the following series.
4, 11, 26, ?, 120, 247
Solution
The pattern in this sequence is as follows:
if w,x,y,z is the sequence.
x=w*2+3
y=x*2+4
z=y*2+5
Let's look at the original sequence.
11 = 4*2+3
26 = 11*2+4
? = 26*2+5
120 = ?*2+6
247 = 120*2+7
$$\Rightarrow$$ ? = 26*2+5=57
