reasoning
Maths Puzzle
Numerical Ability
Number System
Find the 3 digit no. whose last digit is the square root of the first digit and second digit is the sum of the other two digits.
And that number is divisible by 2,3,6,7.What is that number?
Read Solution (Total 5)
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- let xyz be the digits of no.,then
z=sqrt(x)
y=x+z=x+sqrt(x)
so no. is =100x+10y+z
=100x+10(x+sqrt(x))+sqrt(x)
=110x+11*sqrt(x)
if x=1, no. is =121
if x=4, no. is =462
if x=9, no. is =990+33=1023(not 3 digit)
two no's 121 & 462
now no. is divisible by 2,3,6,7
so divisible by LCM OF 2,3,6,7 = 42
only 462 is divisible by 42
ANS 462 - 11 years agoHelpfull: Yes(3) No(1)
- as the no is of only 3 digit so it can be 2 or 3 and this no should be divisible by 2 so last digit is fix i.e 2 so ans will be 462
- 10 years agoHelpfull: Yes(3) No(1)
- If z=squr(x),
. y=x+z.
If x=4=>z=2
Y=x+z=>4+2=6
So.num is 462 - 10 years agoHelpfull: Yes(1) No(1)
- 462
sqr root of 4 is 2
sum of 4 and 2 is 6
and 462 is div by 2 3 6 7 - 8 years agoHelpfull: Yes(0) No(0)
- lcm(2,3,6,7)=42
4+2=6(second number
462 - 6 years agoHelpfull: Yes(0) No(0)
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