Question

There is a 3 digited number. 3rd digit is the square root of the 1st digit. 2nd digit is the sum of 1st and 3rd. And that number is divisible by 2,3,6,7. What is that number?
A) 121
B) 943
C) 462
D) None

Answer 1

There is a 3 digited number. 3rd digit is the square root of the 1st digit. 2nd digit is the sum of 1st and 3rd. And that number is divisible by 2,3,6,7. What is that number?
A) 121
B) 943
C) 462
D) None

=> Option B

Explanation;

Let xyz be the digits of number.

Then

z=sqrt(x)

y=x+z=x+sqrt(x)
so number 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

ANSWER = 462

PROVED

Answer 2

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$<b>$
There is a 3 digited number. 3rd digit is the square root of the 1st digit. 2nd digit is the sum of 1st and 3rd. And that number is divisible by 2,3,6,7. What is that number?
A) 121
B) 943
C) 462✔️✔️
D) None

$\huge\underline{\green {\textbf{}}}$

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