TCS
Company
Numerical Ability
Number System
The sum of the digits of a three digit number is 17, and the sum of the squares of its digits is 109. If we subtract 495 from that number, we shall get a number consisting of the same digits written in the reverse order. Find the number
Read Solution (Total 10)
-
- ans will be 863
sum of the digits= 8+6+3=17
sum of the squares = 64+36+9 = 109
863-495=368 - 11 years agoHelpfull: Yes(22) No(2)
- Its better if we do option verification.
The answer could be 863.
coz we have x+y+z=17
100x+10y+z-495=100z+10y+x ie x-z=5
using this we can have
2z+y=12, by trial and error we have 863 - 11 years agoHelpfull: Yes(17) No(1)
- Let the digits be a,b,c
Given 100a+10b+c=17
and a^2 + b^2 +c^2 =109 --eq (2)
and also 100a+10b+c-495 = 100c+10b+a
=> 99a-99c=495
=> a-c=5
=> a=5+c
take c=1 , so a=6 then b will be 10 which is impossible.
take c=2, so a=7 and b=9 and substitute in eq (2), its not satisfied.
take c=3, so a=8 and b=5 and eq(2) will be 8^2 + 5^2 + 3^2 =109 and also satisfies the given conditions..
so, the number is 853
- 11 years agoHelpfull: Yes(4) No(8)
- x+y+z=17 ---(1),
x2+y2+z2=109 -----(2),
100x+10y+z-495=100z+10y+x
x-z=5 -----(3)
solving 1,2,3 we get x=8,y=6,z=3 - 11 years agoHelpfull: Yes(3) No(0)
- given,
100x+10y+z-495=100z+10y+x
x-y=5
solve it from the option that first and the last digit has the difference of 5 - 11 years agoHelpfull: Yes(2) No(0)
- Sorry friends ..Itz mistyped.. the answer is 863 only..
- 11 years agoHelpfull: Yes(1) No(0)
- let, three numbers be x,y,z
x+y+z=17
x2 +y2+z2=109
now,
495-109=386.
but it is reverse in order.
therefore,
x=6,y=8,z=3
ie x+y+z=6+8+3=17 - 8 years agoHelpfull: Yes(1) No(0)
- Go with Option.. 773 , 944, will not be 109 when added their squares.
for 863,
8+6+3=17,
sqrs: 64+36+9=109,
495-109=386. when we reversed 863 it will be 368.
So the correct answer is 683. if we reversed it we get 386.
ans= 683 - 8 years agoHelpfull: Yes(0) No(0)
- go or option veriation it is very much simple rather than solvin
- 8 years agoHelpfull: Yes(0) No(0)
- The ans is 863
- 8 years agoHelpfull: Yes(0) No(1)
TCS Other Question