Quantitative Aptitude - Arithmetic Ability Questions

the next 2 number in series we need to divide the series into 2 different series

First series : 4 , 6, 12, 30 ??

Second Series : 12,18,26, ??

So we need to see for the pattern for those series in order to find the next two number , we can do this by finding the difference or division , multiplication logic whatever may apply :

• Pattern of Series 1 :

6 divide 4 : 1.5

Next number i.e 12 divided by 6=2

Next number i.e 30 divided by 12 =2.5

So series is going in multiples of 1.5, 2, 2.5, 3 , so on

So first series will look like

4 , 6, 12, 30, 30x3 =90

• Pattern of Series 2 : 12,18,26, ??

Its simple Adding numbers with iterative logic (i.e 6, 8, then followed by 10, 12)

Series will be like 12,18,26,36.

For the next two numbers : Series will be like 4, 12, 6, 18, 12, 26, 30, 36, 90

Given the number series is 4, 6, 12, 30, 81, 315.

Here it follows a pattern that

4

4 x 1.5 = 6

6 x 2 = 12

12 x 2.5 = 30

30 x 3 = 90 not equals to 81

90 x 3.5 = 315

Hence the odd one in the series is 81.

With close observation, you will note that each number in the list is in the middle of two prime numbers. Thus:

4 is in the middle of 3 and 5, 6 is in the middle of 5 and 7, 12 is in the middle of 11 and 13, 18 is in the middle of 17 and 19, 30 is in the middle of 29 and 31. 42 is in the middle of 41 and 43, 60 is in the middle of 59 and 61.

Therefore, the next number would be the one that is in the middle of the next two prime numbers, which is 72 (which is in the middle of 71 and 73).

Terms at odd places are 5, 6, 7, 8 etc. and each term at even place is 16.

So, 9 is wrong.

$$\begin{gathered} ?2 = 2×78-21+8+49-148 \\ = 57 - 21 \\ =36 \\ => ? = ±6 \end{gathered}$$

Let the original salaries of Ravi and Sumit be Rs. 2x and Rs. 3x respectively.
Then,
(2x+4000) / (3x+4000) = 40 / 57
⇒ 57 × (2x + 4000) = 40 × (3x+4000)
⇒ 6x = 68,000
⇒ 3x = 34,000
Sumit's present salary = (3x + 4000) = Rs.(34000 + 4000) = Rs. 38,000