Quantitative Aptitude - Arithmetic Ability Questions

Each of the numbers except 81 is a prime number.

Apply a3 + b3 + c3 - 3abca2 + b2 + c2 - ab - bc - ca = a + b + c

Hence the answer is  1.5 + 4.7 + 3.8 = 10.

In each number except 383, the product of first and third digits is the middle one.

Each of the numbers except 28, is a multiple of 3.

Given 92613 x 62742241 = ? + 89

Using unit digit method,

On LHS,

1 x 1 x 1 = 1

sqrt of last digit 1 => it must end with either 9 or 1

so now

1 x 1 = 1

1 x 9 = 9

On RHS,

? + 89

=> ? = ...1 - 89 = last digit is 11- 9 = 2

or

=> ? = ...9 - 89 = last digit is 9 - 9 = 0

Here in the options last digit 2 is option C.

Each day of the week is repeated after 7 days. So, after 63 days, it will be Monday.

After 61 days, it will be Saturday.

We know that d=√2s 

Given diagonal = 20 cm 

=> s = 20/2 cm

Therefore, perimeter of the square is 4s = 4 x 20/2 = 402   cm.

Here the given series is 396, 462, 572, 427, 671, 264.

In all the terms, the middle digit is the sum of first and third digit except 427.

So the Odd number in the given series is 427.