Exams

Here the series follows the pattern that, product of succesive prime numbers i.e,

 2 × 3 = 6

 3 × 5 = 15

 5 × 7 = 35

 7 × 11 = 77

 11 × 13 = 143

 13 × 17 = 221

 17 × 19 = 323

So here in place of 77 the number 63 is written.

So the wrong number is 63.

Here in the given number series 49, 81, 121, 169, 196, 225

Except 196 all others are squares of odd numbers, whereas 196 is a square of 14 which is an even number.

Hence, the odd man in the given number series is 196.

From the beginning, the next term comes by adding prime numbers in a sequence of 2, 3, 5, 7, 9, 11, 13... to its previous term. But 165 will not be in the series as it must be replaced by 166 since 153+13 = 166.

As per the BODMAS rule, Addition and subtraction can be treated on same priority (from left to right) when they are in consecutive order.

65% × 700 + 14 - 9 × 3 65 × (700/100) + 14 - 27 455 + 14 - 27 = 442

20% of a = b 

=> (20/100) * a = b 

 b% of 20 =(b/100) x 20 = [(20a/100)  / 100] x 20= 4a/100 = 4% of a.