Quantitative Aptitude - Arithmetic Ability Questions

5/8 = .625, 7/12 = .5833, 3/4 = .75, 13/16 = .8125

So order will be
7/12 < 5/8 < 3/4 < 13/16

Given (3 Men + 4 Women + 6 Children) -----> 9 days

But W = 2M and C = M/2

Now, convert Men and Children into Women by

$$\begin{gathered} 3W2 + 4W + 6W4 \\ => 32 + 4 + 32 = 7 Women \end{gathered}$$ 

Therefore, 7 women alone can complete this work in 9 days.

Speeds of two trains = 30 kmph and 58 kmph

=> Relative speed = 58 - 30 = 28 kmph = 28 x 5/18 m/s = 70/9 m/s

Given a man takes time to cross length of faster train = 18 sec

Now, required Length of faster train = speed x time = 70/9  x  18 = 140 mts.

Let present ages of Sumit=w, Krishna=x, Rishabh=y and Rohit=z , then
w+x+y = 43x3 = 129 ---(i) and
w+y+z = 49x3 = 147 ---(ii)
Subtracting (i) from (ii), (w+y+z) - (w+x+y)=147 -129 , z- x =18 ---(iii)
Given Rohit's age => z = 54, so from (iii), x = 54-18 = 36

Let the inner and outer radii be r and R metres.

Then  2πR=3527=>R=3527*722*12=8m 

 2πR=5287=>R=5287*722*12=12m

=> Width of the ring = (R - r) = (12 - 8) m = 4 m.

The smallest possible number of books = L.C.M of 5, 9 and 13.
Therefore, L.C.M of 5,9 and 13 is = 5 x 9 x 13 = 585.

Let the interest rate be r%

We know that,

S.I = PTR/100

=> (1540 x 5 x r)/100  +  (1800 x 4 x r)/100 = 1788

=> r = 178800/14900 = 12%