TCS
Company
Logical Reasoning
General Mental Ability
Find The Sum Of All 4-Digit Numbers, that can be formed from the digits 0,1,3,4,5 without repetition.
a)259974
b)337974
c)346632
d)334554
Read Solution (Total 8)
-
- it's very simple.
n=5 i.e 0,1,3,4,5
1.for thousandth position we can use only 1,3,4,5.(can not use 0)
add numbers i.e 1+3+4+5=13
thousandth position sum=1000*13*(n-1)!=1000*13*24
2.hundredth position sum=100*13*(n-1)!=100*13*24
3.tenth position sum=10*13*(n-1)=10*13*24
4.unit position sum=1*13*24
5.13*24=312
6.so sum of all 312(1000+100+10+1)
i.e 312*1111
=346632
i.e option c
thank you
- 11 years agoHelpfull: Yes(19) No(1)
- b)337974
Trying to explain sol of DIPIN.
Total 96 numbers can be formed.
No number can start with 0.
no. of numbers starting with 1 or 3 or 4 or 5 = 4*3*2*1=24
when no is starting with 1,
0,3,4,5.. each number will appear in unit place 6 times.
so (0+3+4+5)*6 = 72
when no is starting with 3,
0,3,4,5.. each number will appear in unit place 6 times.
so (0+1+4+5)*6 = 60
when no is starting with 4,
0,3,4,5.. each number will appear in unit place 6 times.
so (0+3+1+5)*6 = 54
when no is starting with 5,
0,3,4,5.. each number will appear in unit place 6 times.
so (0+3+4+1)*6 = 48
sum of digits at unit place of all numbers = 234
sum of digits at tens place of all numbers = 234
sum of digits at hundreds place of all numbers = 234
sum of digits at thousands place of all numbers = 312
adding these values, we get the sum all 4 digit numbers that can be formed from the digits 0,1,3,4,5 without repetition = 3579974. - 13 years agoHelpfull: Yes(14) No(3)
- 337974
Taking help of solution given by shikha,
Total 96 numbers can be formed.
No number can start with 0.
no. of numbers starting with 1 or 3 or 4 or 5 = 4*3*2*1=24
sum of digits at unit place of all numbers = 234
sum of digits at tens place of all numbers = 234
sum of digits at hundreds place of all numbers = 234
sum of digits at thousands place of all numbers = 312
considering this , sum of all 4 digit numbers that can be formed from the digits 0,1,3,4,5 without repetition = 337974 - 13 years agoHelpfull: Yes(13) No(10)
- @ Anup,
I think it is well explained by Dimple and Dipin.
b)337974 should be correct.
Trying to explain sol of DIPIN and Dimple.
Total 96 numbers can be formed.
No number can start with 0.
no. of numbers starting with 1 or 3 or 4 or 5 = 4*3*2*1=24
when no is starting with 1,
0,3,4,5.. each number will appear in unit place 6 times.
so sum of digits at unit place =(0+3+4+5)*6 = 72
when no is starting with 3,
0,1,4,5.. each number will appear in unit place 6 times.
so sum of digits at unit place=(0+1+4+5)*6 = 60
when no is starting with 4,
0,3,1,5.. each number will appear in unit place 6 times.
so sum of digits at unit place=(0+3+1+5)*6 = 54
when no is starting with 5,
0,3,4,1.. each number will appear in unit place 6 times.
sosum of digits at unit place = (0+3+4+1)*6 = 48
sum of digits at unit place of all numbers = 234 - 13 years agoHelpfull: Yes(4) No(2)
- Simple Formula = n!*(Sum of Given Digits)* (1111 for 4 digit 111 for 3 digit).
for given situation n = 4, sum of digit = 0+1+3+4+5 = 13.
sum = 4! (13) * (1111) = 346634 - 10 years agoHelpfull: Yes(2) No(0)
- dipin can u explain how this
sum of digits at units palce of all nos=234 - 13 years agoHelpfull: Yes(1) No(3)
- Total 96 numbers can be formed.
No number can start with 0.
no. of numbers starting with 1 or 3 or 4 or 5 = 4*3*2*1=24
sum of digits at unit place of all numbers = 234
sum of digits at tens place of all numbers = 234
sum of digits at hundreds place of all numbers = 234
sum of digits at thousands place of all numbers = 234
sum of digits at ten thousands place of all numbers = 312
considering this , sum of all 4 digit numbers that can be formed from the digits 0,1,3,4,5 without repetition = 3579974 - 13 years agoHelpfull: Yes(0) No(4)
- Dipin please explain
- 13 years agoHelpfull: Yes(0) No(2)
TCS Other Question
THE AVERAGE TURNOVER OF A COMPANY IN JAN, FEB, MAR IS 12 CRORE WHILE THAT OF MAR, APR, MAY, JUNE IS 14 CRORE. WHAT IS THE TURNOVER IN MARCH IF AVERAGE FOR THE FIRST HALF OF THE YEAR IS 12 CRORE.
. 36 people {a1, a2, …, a36} meet and shake hands in a circular fashion. In other words,
there are totally 36 handshakes involving the pairs, {a1, a2}, {a2, a3}, …, {a35, a36}, {a36,
a1}. Then size of the smallest set of people such that the rest have shaken hands with at least
one person in the set is
a)12 b)11 c)13 d)18