The sum of three numbers is 132, If the first number be twice the second and third number be one-third of the first, then the second number is?

Let the value for ? be N
So N x 9 x 7 x 3 = a number with unit digit 1.
Clearly, the minimum value of N is 9.

Let x/5 = p and let y when divided by 5 gives q as quotient and 1 as remainder.
Then, y = 5q + 1
Now x = 5p and y = 5q + 1
? x + y = 5p + 5q + 1 = 5(p + q) + 1
So, required remainder = 1

Let the second number be N.
Then, first number = 2N and third number = 4N
? 2N + N+ 4N/3 = 56
? 7N = 3 x 56
? N = 3 x 56/7 = 24
So, the smallest number is 24.

A number that ends in 2 , 3 , 7 or 8 is never a perfect square.

6² -1 = 35, which is divisible by both 5 and 7.

Let unit digit = x and ten's digit = y
3(x + y)= 10y + x .....(i)
10y + x + 45 = 10x + y ....(ii)

2x - 7y = 0.9x -9y = 45
or x - y = 5 .... (iii)

Solving these equations, we get
x=7, y=2
? Required number = 27

Let the required fraction be p/q.
Then, (p +1) / (q +1) = 4
? p - 4q= 3 ....(i)

And, (p - 1) / (q -1) = 7
? p - 7q = -6 ....(ii)

Solving these equation we get p = 15, q=3

Let the number be a and b .
Then a² + b² = 68 ....(i)
and (a - b)² = 36
Now, (a - b)² = 36 ....(ii)
? a² + b² - 2ab = 36
? 68 - 2ab = 36
? 2ab = 32
? ab = 16 .

Let the numbers be x and y ,
Then, 2x + 3y = 18 ....(i),
3x + 2y = 17 ....(ii)

Solving, we get x =3 , y= 4
? Largest number = 4

Let the number be x, y, z
Then,
x + y = 45,
y + z = 55,
z + 3x = 30

Now, y = (45 - x) and
z = 55 - y
? z = 55 - (45 - x ) = 10 + x

? 10 + x + 3x = 90
? x = 20
So, third number = z
= 10 + x = 30