Quantitative Aptitude - Arithmetic Ability Questions

Let the required number be 'p'.

From the given data,

p + 12 = 160 x 1/p

=> p + 12 = 160/p

=> p(p + 12) = 160

=> P^2 + 12p - 160 = 0

=> p^2 + 20p - 8p - 160 = 0

=> P(p + 20) - 8(p + 20) = 0

=> (p + 20)(p - 8) = 0

=> p = -20 or p = 8

As, given the number is a natural number, so it can't be negative.

Hence, the required number p = 8.

To convert a fraction into decimal, just take the number on top which we called the numerator and divide it by the number at the bottom which we called the denominator.

2/3

How it comes :

$2÷3=0$ bring down the decimal point.

$20÷3=6$ and carry the remainder $2$ to make $20$

$20÷3=6$ and carry the remainder $2$ to make $20$

$20÷3=6$ and carry the remainder $2$ to make $20$

etc...

This gives the recurring decimal 0.6666...

If we round off to two decimals , then it becomes 0.67.

Hence, decimal fraction of 2/3 = 0.67.

$$\begin{gathered} 3 \\ 32 + 3 = 12 \\ 5 \\ 52 + 5 = 30 \end{gathered}$$

i=j/m

Out of 9 persons,4 can be choosen in 9C4 ways =126.

Favourable events for given condition = 2C2*7C2= 21.

So,required probability = 21/126 =1/6.

F=BD×TDBD-TD=200×100200-100=200×100100=Rs.200

Number of ways of selecting (3 consonants out of 7) and (2 vowels out of 4) =( C37×C24 ) = 210.

Number of groups, each having 3 consonants and 2 vowels =210

Each group contains 5 letters.

Number of ways of arranging 5 letters among themselves = 5! = 120. 

Required number of words = (210 x 120) = 25200.