Explanation

15 + 6 = 21

21 + 9 = 30

30 + 12 = 42

42 + 15 = 57

Explanation

Let the number x, added 3, then doubled the sum = 40 

40 - 6 = 34 

34 divided by 2 = 17

Explanation

10, 20, 31, 43, 54, 70.

10, 18, 28, 40, 56, 70.

10 + 8 = 18

18 + 10 = 28

28 + 12 = 40

40 + 14 = 54

54 + 16 = 70

Explanation

HCF Stand for Highest Common factor

So the HCF of 60 and 72 is 2 × 2 × 3 which is 12.

..........

The lowest common multiple is found by multiplying all the factors which appear in either list

...........

So the LCM of 60 and 72 is 2 × 2 × 2 × 3 × 3 × 5 which is 360.

SH5-9-2023

Explanation

All numbers are repeated except 4 and 8.

Multiply 8 by 4 = 32

Explanation

New annual salary = $90,000

Salary increase = $15,000.

Original salary = $90,000 - $15,000.

= $75,000

%Increase = ($15,000/ $75,000 )*100

=20%

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