Fill in the blanks : 197 T 99, 226 S 120, 257 R 143, __________, 325 P 195.
290 Q 168
First numbers: 197, 226, 257, ?, 325 with differences +29, +31, +33, +35
257 + 33 = 290, and 290 + 35 = 325
Letters: T, S, R, ?, P move one step back in the alphabet, so the missing letter is Q.
Last numbers: 99 = 10² - 1, 120 = 11² - 1, 143 = 12² - 1, so the next is 13² - 1 = 168, followed by 14² - 1 = 195.
Check: the missing term is 290 Q 168, and all three parts fit their patterns up to 325 P 195.
Hence, 290 Q 168.
Important Questions from Mixed Series
Find the missing term in the following series:
2A11, 4D13, 12G17, 48J23, _______
Select the number from among the given options that can replace the question mark (?) in the following series.
6Q9, ____, 20Y23, 27C30
A sequence is given, of which one term is incorrect. Select the wrong term from the given alternatives.
PC81, SG130, VK179, YO228, BS277, EX326
A series is given with one term missing. Choose the correct option from the given alternatives that will complete the series.
LT121, PP169, TL289, XH361, BD529, ?
A series is given with one term missing. Choose the correct option from the given ones that will complete the series.
MD41, OI80, QN119, SS158, UX197,?
