GATE Questions

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Given monday population = 3000
Per day 20% increase in population.

Tuesday population = 3000 + 3000x20/100 = 3000 + 600 = 3600

Wednesday population =3600 + 3600x20/100 = 3600 + 720 = 4320

Thursday population = 4320 + 4320x20/100 = 4320 + 864 = 5184

So that day is Thursday.

Let length, breadth and height of the room be 7, 3, 1 unit respectively.

Area of walls = 2(l+b)xh = 2(7+3)x1 = 20 sq. unit.

Now, length, breadth and height of room will become 3.5, 6 and 2 respectively. 

Area of walls = 2(l+b)xh = 2(3.5+6)x2 = 38 sq. unit. 

% Increase in the area of walls = (38-20)x100/20 = 90%.

  LCD is nothing but Lowest or Least Common Denominator

Here LCD of 12 and 18 means LCD of two fractions with denominators 12 and 18 respectively.

Therefore, LCM of 12 & 18 = 6 x 3 x 2 = 36 

•  How to calculate LCD ::

The lowest common denominator or least common denominator (LCD) is the least common multiple (LCM) of the denominators of a set of fractions.

Let the five consecutive odd numbers be x-4, x-2, x, x+2, x+4

According to the question,

Difference between square of the average of first two odd number and the of the average last

two odd numbers is 396

i.e, x+3 and x-3

$$\begin{gathered} ⇒x + 32 - x - 32 = 396 \\ ⇒ x2 + 9 + 6x - x2 + 6x - 9 = 396 \\ ⇒ 12x = 396 \\ ⇒ x = 33 \end{gathered}$$

Hence, the smallest odd number is 33 - 4 = 29.

3

3 x 1.5 + 1.5 = 6

6 x 2.5 + 2.5 = 17.5

17.5 x 3.5 + 3.5 = 64.75

64.75 x 4.5 + 4.5 = 295.875

From the given information,

F1M → F is the wife of M
M3K → M is the father of K
Therefore, F is the mother of K.

Let the place be at a distance of 'd' kms

From the given data,

$$\begin{gathered} d5 - 1 + d5 + 1 = 7560 kms \\ d4 + d6 = 54 \\ \end{gathered}$$

5d/12 = 5/4 => d = 3 kms.

Hence, the place is 3 kms far.

Let the two-digit number be 10a + b
a + b = 12 --- (1)
If a>b, a - b = 6
If b>a, b - a = 6
If a - b = 6, adding it to equation (1), we get
2a = 18 => a =9
so b = 12 - a = 3
Number would be 93.
if b - a = 6, adding it to the equation (1), we get
2b = 18 => b = 9
a = 12 - b = 3.
Number would be 39.
There fore, Number would be 39 or 93.