GATE Questions

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Given S = 17 yrs

A = 16 yrs

B = 12 yrs

Average = 17 + 16 + 12/3 = 15 yrs

Given if Aslam added to them, their average increases by 5

=> Average of 4 members = 20

Let the age of Aslam be 'x'

Then, 

17 + 16 + 12 + x /4 = 20

=> x = 80 - 45

=> x = 35. 

Hence, the age of Aslam is 35 yrs.

Days remaining 124 – 64 = 60 days

Remaining work = 1 - 2/3 = 1/3

Let men required men for working remaining days be 'm'

So men required = (120 x 64)/2 = (m x 60)/1 => m = 64

Men discharge = 120 – 64 = 56 men.

x – y = 5

4x – 6y = 6

x = 12 y = 7

Given total number of cows = k
Now, 1st son share = k/2
2nd son share = k/4
3rd son share = k/5
4th son share = 9

(k) + (k/4) + (k/5) + 9 = k
=> k - (19k/20) = 9
=> (20k-19k)/20 = 9
=> k = 180.

Let wholesaler dealers marked price = 100%, Retailer's C.P = 80%
And the retailer sells at 5% less than the marked price => S.P = 95%
If S.P of 95% of the retailer costs Rs.19 to customer,so its C.P of 80% will cost 80 x 19/95 = 16
Profit made by the retailer = 19-16 =  Rs.3

As Microphone makes sound louder similarly Microscope makes the object magnified.

Hence, Microphone : Loud :: Microscope : Magnify.

Given, y/(x - z) = (y + x)/z = x/y
yz = xy + x2 - yz - xz ....(1)
Also xy = yx-z ⇒x2 -xz = y2 ....(2)
Using (1) and (2), we get yz = xy - yz + y2
2yz = xy + y2
2z = x + y
Only option (B) satisfies the equation.

Here as given Q is in the middle and it satisfies all other conditions given in the question.