The number series below is made by writing the same group of numbers again and again.
5 8 2 8 8 3 5 8 2 8 8 3 5 8 2
If the series is continued in the same way, at which place (counted from the left) will the 20th 8 appear?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → 40th
Find how many 8’s one full group holds, count the full groups needed, then find the place of the remaining 8’s inside the following group.
The repeating group is 5 8 2 8 8 3 (6 numbers); 8 is at its 2nd, 4th and 5th places, so each group has three 8’s
6 full groups hold \(6\times3=18\) eights and end at place \(6\times6=36\)
The 19th and 20th eights are the first two 8’s of the 7th group, at its 2nd and 4th places
Place of the 20th 8 \(=36+4=40\), that is the 40th place