Explanation

11 × 15 = 165

11 × 19 = 209

12 × 15 = 180

11 × 19 = 228

Explanation

HCM of 120 is not 74.

There, B is the correct option

HCF: Highest Common factor

Explanation

180 - 55 = 155

Explanation

6 + 6 = 12

12 + 9 = 21

21 + 12 = 33

33 + 15 = 48

Explanation

3 × 3 = 9 - 1 = 8

8 × 3 = 24 - 2 = 22

22 × 3 = 66 - 3 = 63

63 × 3 = 189 - 4 = 189

Explanation

13 × 2 = 26 - 2 = 24

24 × 2 = 48 - 2 = 46

46 × 2 = 92 - 2 = 90

90 × 2 = 180 - 2 = 178

Explanation

Let suppose original price = x

25% of x 25% X x

x- 25%x = 900

x - 25/100 x = 900

100x - 25x = 90000

75x = 90000

x=1200

Explanation

The given sequence is:

3, 4, 7, 8, 11, 12

Form differences between two consecutive numbers in the sequence as follows:

4 - 3 = 1

7 - 4 = 3

8 - 7 = 1

11 - 8 = 3

12 - 11 = 1

X- 12 = 3

= 15

Explanation

We see that 32 + 8 = 40 and 32 – 8 = 24. Now let us check this rule for one more term. We see that 16 + 8 = 24. Therefore this works for more than half of the given numbers. Hence the rule is correct. Therefore the missing number in the series is 16 – 8 =  8. The answer is  8.

Explanation

If each group comprises of 2 handshakes than total handshakes of all the individuals are 120*2 handshakes = 240

taking Lcm 240 = 16*15 hence 16 persons in total