Verbal Reasoning - Mental Ability Questions

Given 7 + 7/7 + 7 x 7 - 7

By using BODMAS rule,

7 + 1 + 7 x 7 - 7

= 8 + 49 - 7

= 57 - 7

= 50.

Hence 7 + 7/7 + 7 x 7 - 7 = 50.

Here given formula is 

a2 + b2 + c2 -ab- bc - ca = 0

and it is possible if and only if a = b = c.

From the trial and error method, 

1) Let a = b = c = 1

Now substitute these values of a, b, c in the above formula.

We get 1 + 1 + 1 - 1 - 1 - 1 = 3 - 3 = 0

2) Now, let a = b = c = 4

Now substitute these values of a, b, c in the above formula.

We get 16 + 16 + 16 - 16 - 16 - 16 = 48 - 48 = 0.

Hence, it is possible that 

a2 + b2 + c2 -ab- bc - ca = 0 iff a = b = c.

The letters in the second and third rows are five steps ahead of those in the first and second trespectively.
So, the missing letter will be five steps ahead of F, which is K.

Divisibility rule for 24 is the number should be divisible by 3 and 8. As we know that 24 = 3 x 8

Now, 

Divisibility rule for 3 :

If the sum of the digits of a number is divisible by 3, then the number is divisible by 3.

Divisibility rule for 8 :

The last three digits of a number should be divisible by 8.

Hence, check for the given options,

A) 37804 => 804 is not divible by 8.

C) 36718 => 718 is not divible by 8.

D) 53810 => 810 is not divible by 8.

B) 2015736 => 736 is divisble by 8 and sum 2 + 0 + 1 + 5 + 7 + 3 + 6 = 24 which is divisible by 3.

Hence, 2015736 is divisible by 24.