The letter series below is made by writing the same group of letters again and again.
C A B A D C A B A D C A B A D
If the series is continued in the same way, at which place (counted from the left) will the 15th A appear?
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → 37th
Find how many A’s one full group holds, count the full groups needed, then find the place of the next A inside the following group.
The repeating group is C A B A D (5 letters); A is at its 2nd and 4th places, so each group has 2 A’s
7 full groups hold \(7\times2=14\) A’s and end at place \(7\times5=35\)
The 15th A is the first A of the 8th group, which is the 2nd letter of that group
Its place \(=35+2=37\), that is the 37th place