CAT Questions

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Let cost of each cell phone = Rs.100 & Sale = 100 phones.

Money receipt = Rs.(100 x 100) = Rs.10,000

New cost per cellphone = Rs.120 and New sale = 70 phones

New Money Receipt = Rs.(70 x 120) = Rs.8400

Then the effect of sales = decrease in money receipt = 

160010000 x 100 = 16%.

Given A,B,C can complete a work in 15,20 and 30 respectively.

The total work is given by the LCM of 15, 20, 30 i.e, 60.

A's 1 day work = 60/15 = 4 units

B's 1 day work = 60/20 = 3 units

C's 1 day work = 60/30 = 2 units

(A + B + C) worked for 2 days = (4 + 3 + 2) 2 = 18 units

 Let B + C worked for x days = (3 + 2) x = 5x units

C worked for 2 days = 2 x 2 = 4 units

Then, 18 + 5x + 4 = 60

22 + 5x = 60

5x = 38

x = 7.6

Therefore, total number of days taken to complete the work = 2 + 7.6 + 2 = 11.6 = 11 3/5 days.

Let M, N and O worked together for x days.

From the given data,
M alone worked for 8 days
M,N,O worked for x days
N, O worked for 1 day

But given that
M alone can complete the work in 18 days
N alone can complete the work in 36 days
O alone can complete the work in 54 days

The total work can be the LCM of 18, 6, 54 = 108 units

M's 1 day work = 108/18 = 6 units
N's 1 day work = 108/36 = 3 units
O's 1 day work = 108/54 = 2 units

Now, the equation is
8 x 6 + 11x + 5 x 1 = 108
48 + 11x + 5 = 108
11x = 103 - 48
11x = 55
x = 5 days.

Hence, all M,N and O together worked for 5 days.

Railway Minister Suresh Prabhu on 18th March, 2017 flagged off the first fully India-made suburban train 'Medha'. The train will save foreign exchange worth ₹32 crore per rake along with 25% saving in the manufacturing cost. It can run at a maximum speed of 105 km per hour, and has been fitted with LED lights and GPS-based passenger information system.

Let the required height of the building be x meter

More shadow length, More height(direct proportion)

Hence we can write as

(shadow length) 40.25 : 28.75 :: 17.5 : x
⇒ 40.25 × x = 28.75 × 17.5
⇒ x = 28.75 × 17.5/40.25
= 2875 × 175/40250
= 2875 × 7/1610
= 2875/230
= 575/46
= 12.5 cm

Let the smallest number be x.
Then larger number = (x + 1365)
x + 1365 = 6x + 15
= 5x = 1350
x = 270
Smaller number = 270.

As,

 A→+2C

 F→+2H

Similarly,

 $$\begin{gathered} K→+2M \\ T→+2V \end{gathered}$$