Latest TCS Aptitude Question SOLUTION: 1, 2, 3 and 4 can form 256 different four digit numbers. If digits repeated, two of them are 1111 and 1113. Then find the sum of 256 numbers. a)711040 b)711000 c)711038 d)711042

• Placement Papers
• /
• TCS
• /
• Numerical Ability
• /
• Permutation and Combination

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

(#M40165033) TCS Numerical Ability question Permutation and Combination Keep an EYE

1, 2, 3 and 4 can form 256 different four digit numbers. If digits repeated, two of them are 1111 and 1113. Then find the sum of 256 numbers.

a)711040 b)711000 c)711038 d)711042

Asked In TCS Suriya Varshini (6 years ago)

Solved ROHIT VAISAY Read Solution (6)

Is this Puzzle helpful?   (79)   (26) Submit Your Solution Permutation and Combination

Read Solution (6) :

pavish  (6 years ago)

s=n/2(a+L)
s= 256/2(1111+4444)
s=711040

Is this solution Helpfull? Yes (49) | No (7)  

sonal gupta  (6 years ago)

4^4=256 ways
(1+2+3+4)/4=5/2
256 *5/2*(1000+100+10+1)=711040

Is this solution Helpfull? Yes (14) | No (1)  

ROHIT VAISAY  (6 years ago) Best Solution

As each digit of four digit number (abcd) can take 4 options (1, 2, 3, 4) total there can be 4^4 numbers.

Obviously each digit (a, b, c, and d) will take the value of 1, 2, 3, 4 equal number of times, so each digit will take the value of 1, 2, 3, 4 - 444=43=64444=43=64 times: units digit will take the values of 1, 2, 3, 4 - 64 times and the same with tens, hundreds, thousands digits.

So the sum would be 64*(1+2+3+4)+64*10*(1+2+3+4)+64*100*(1+2+3+4)+64*1000*(1+2+3+4)=64*10*(1+10+100+1000)=711040.


Hope it helps.

Is this solution Helpfull? Yes (12) | No (11)  

shashi  (6 years ago)

Sn = n/2 (a+L)
=256/2 (1111+4444)
=711042

Is this solution Helpfull? Yes (10) | No (1)  

Prikshit Gakhar  (5 years ago)

(N)^(n-1)*(sumofdigits)*(111....ntimes)

Is this solution Helpfull? Yes (3) | No   

Anandhraja  (4 years ago)

(N)^(n-1)*(sumofdigits)*(111....ntimes)
711040

Is this solution Helpfull? Yes | No   

Please Login to Read Solution.