Latest TCS Aptitude Question SOLUTION: 1,5,6,25,26,30,31,125,126,130,131,150,151,155,156,………What is the value of 30th term in the given series?(a)781(b)3125(c)776(d) 780

• Placement Papers
• /
• TCS

TCS Question Papers: TCS Interview Experience(90) TCS Company Profile

(#M40013143) TCS question Keep an EYE

1,5,6,25,26,30,31,125,126,130,131,150,151,155,156,………What is the value of 30th term in the given series?(a)781(b)3125(c)776(d) 780

Asked In TCS viru (11 years ago)

Unsolved Read Solution (8)

Is this Puzzle helpful?   (6)   (0) Submit Your Solution

Read Solution (8) :

VANYA BANSAL  (11 years ago)

the answer will be 780.
as we can see the 2,4,6,8,10...positions
all are multiple of 5 with digits one after and the odd digits are +1 to that
so the sequence is like 5*5 for the 4th position and +1 to the 5th position
same manner 6th position 5*6 n 7th is 5*6+1
8th is multiplying the 2nd n 4th position n 9th is +1 to that
10th place is multiplying the 2nd n 5th position n 11th is +1 to that

in the same way for 30th position...
we will multiply 5 with the 15th position i.e. 5*156

Is this solution Helpfull? Yes (9) | No (2)  

Jagjeet   (11 years ago)

b) 3125

1,5,1+5
1,5,6,25,25+1,25+5,25+6
1,5,6,25,26,30,31,125,125+1,125+5,125+6,125+25,125+26,125+30,125+31
1,5,6..............................................................,625,625+1...
this will cover 29th term then next will be 3125

Is this solution Helpfull? Yes (4) | No (1)  

DURGA SATISH  (11 years ago)

jagjeet u r excellent

Is this solution Helpfull? Yes (2) | No   

Prashant  (11 years ago)

780..:)
1 5 6 25 26 30 31 125 126 130 131 150 151 155 156 625 626 630 631 650 651 655 656 750 751 755 756 775 776 780 781.

Logic - Given above by Jagjeet.

Is this solution Helpfull? Yes (2) | No (1)  

saurabh agarwal  (11 years ago)

156*5=780

Is this solution Helpfull? Yes (2) | No (1)  

divyang  (10 years ago)

1,
5 =(5*1)=(5*1st term), 6=(5+1) ,
25=(5*5)=(5*2nd term), 26=(25+1),
30=(5*6)=(5*3rd term), 31(30+1) ,
125=(5*25)=(5*4th term), 126=(125+1),
And so on
14th term =155=(5*31)
15th term =155+1 =156
And 30th term = 5*15th term =5*156=780

Is this solution Helpfull? Yes (2) | No   

ramya  (11 years ago)

answer will be 781.observe the sequence, we find that the numbers in even positions are always odd.so as 30th term is an even position, the answer must be an odd number.so options (c) and (d) are wrong.option (b) is also wrong as it cant be that large.so i think it is option (a)781

Is this solution Helpfull? Yes | No (7)  

shubham yerpude  (8 years ago)

1,
5 =(5*1)=(5*1st term), 6=(5+1) ,
25=(5*5)=(5*2nd term), 26=(25+1),
30=(5*6)=(5*3rd term), 31(30+1) ,
125=(5*25)=(5*4th term), 126=(125+1),
And so on
14th term =155=(5*31)
15th term =155+1 =156
And 30th term = 5*15th term =5*156=780

Is this solution Helpfull? Yes | No   

Please Login to Read Solution.