Quantitative Aptitude - Arithmetic Ability Questions

At 3 o'clock, the minute hand is 15 min. spaces apart from the hour hand. 

 To be coincident, it must gain 15 min. spaces. 

 55 min. are gained in 60 min.

  Then 15 min spaces are gained in  = 6055×15 min. 

Therefore,  The hands are coincident at  16411 min. past 3 o'clock.

You need two points to draw a line. The order is not important. Line AB is the same as line BA. The problem is to select 2 points out of 3 to draw different lines. If we proceed as we did with permutations, we get the following pairs of points to draw lines.

AB , AC

BA , BC

CA , CB

There is a problem: line AB is the same as line BA, same for lines AC and CA and BC and CB.

The lines are: AB, BC and AC ; 3 lines only.

So in fact we can draw 3 lines and not 6 and that's because in this problem the order of the points A, B and C is not important.

Let each installment be Rs.x. Then, 

(P.W. of Rs.x due 1 year hence) + (P.W of Rs.x due 2 years hence) + (P.W of Rs. X due 3 years hence) = 7620.

x1+503x100+x1 +503x1002+x1 +503x1003 = 7620

 6x7+36x49+216x343=7620

 294x + 252x + 216x = 7620 x 343

 => x = 3430

 Amount of each installment = Rs.3430

Water in 60 gm mixture=60 x 75/100 = 45 gm. and Milk = 15 gm.

After adding 15 gm. of water in mixture, total water = 45 + 15 = 60 gm and weight of a mixture = 60 + 15 = 75 gm.

So % of water = 100 x 60/75 = 80%.

Length of largest tile = H.C.F. of 1517 cm and 902 cm = 41 cm. 

Area of each tile = 41×41cm2  

Required number of tiles  = 1517×90241×41= 814

Speed of Boy is B = 4.5 kmph

Let the speed of the stream is S = x kmph

Then speed in Down Stream = 4.5 + x

speed in Up Stream = 4.5 - x

As the distance is same,

=> 4.5 + x = (4.5 - x)2

=> 4.5 + x = 9 -2x

3x = 4.5

x = 1.5 kmph