Quantitative Aptitude - Arithmetic Ability Questions

Given number sequence is 28, 16, 28, 76, 274

Here the sequence follows a pattern that

28

28 x 0.5 + 2 = 14 + 2 = 16

16 x 1.5 + 4 = 24 + 4 = 28

28 x 2.5 + 6 = 70 + 6 = 76

76 x 3.5 + 8 = 266 + 8 = 274

274 x 4.5 + 10 = 1233 + 10 = 1243

Hence, the next number in the given number sequence is 1243.

Man's rate in still water = (15 - 2.5) km/hr = 12.5 km/hr.

Therefore,  Man's rate against the current = (12.5 - 2.5) = 10 km/hr.

The above given sequence follows a pattern that,

$$\begin{gathered} 1 \\ 22 = 4 \\ 33 = 27 \\ 44 = 256 \\ 55 = 3125 \\ 66 = 46656 \\ and so on... \end{gathered}$$

Therefore, the next two numbers in the given sequence is 256 & 3125.

The word 'LEADING' has 7 different letters.

When the vowels EAI are always together, they can be supposed to form one letter.

Then, we have to arrange the letters LNDG (EAI).

Now, 5 (4 + 1) letters can be arranged in 5! = 120 ways.

The vowels (EAI) can be arranged among themselves in 3! = 6 ways.

Required number of ways = (120 x 6) = 720.