Quantitative Aptitude - Arithmetic Ability Questions

(16 – 2)! × 2 = 14! × 2

From the given data in the question,

$$\begin{gathered} 279841 = 160000 x 1+15100t \\ 279841160000 = 115100t \end{gathered}$$

t = 4 years.

First find the present value of $3800,then compare present values:

M  = p(1+i/4)^4n

Let workdone 1 boy in 1 day be b

and that of 1 girl be g

From the given data,

4(5b + 3g) = 23

20b + 12g = 23 .......(a)

2(3b + 2g) = 7

6b + 4g = 7 ........(b)

Solving (a) & (b), we get

b = 1, g = 1/4

Let number og girls required be 'p'

6(7 x 1 + p x 1/4) = 45

=> p = 2.

Hence, number of girls required = 2

Ans. 
Distance covered by 1st train in 4 hours = 80*4 = 320 km
Relative speed of 2nd train = 120-80 = 40 km
It will overtake another train in 320/40 = 8 hours
Distance between overtake point and station A = 8*120 = 960 km

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.

Now, the principal amount P = Rs. 1,45,440

Rate of interest R = 20%/annum

Now monthly income I = PTR/100 = 1,45,440 x 20 x 1/100 x 12

= 2908800/1200

= Rs. 2424.

Hence, her monthly income = Rs. 2424.