GATE Questions

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Copper Iodide is the systematic name of the given compound (CuI)s.

For solving this problem first we would break the whole range in 5 sections

1) From 1 to 9
Total number of zero in this range = 0

2) From 10 to 99
Total possibilities = 9*1 = 9 ( here 9 is used for the possibilities of a non zero integer)

3) From 100 to 999 - three type of numbers are there in this range
a) x00 b) x0x c) xx0 (here x represents a non zero number)
Total possibilities
for x00 = 9*1*1 = 9, hence total zeros = 9*2 = 18
for x0x = 9*1*9 = 81, hence total zeros = 81
similarly for xx0 = 81
total zeros in three digit numbers = 18 + 81 +81 = 180

4) From 1000 to 9999 - seven type of numbers are there in this range
a)x000 b)xx00 c)x0x0 d)x00x e)xxx0 f)xx0x g)x0xx
Total possibilities
for x000 = 9*1*1*1 = 9, hence total zeros = 9*3 = 27
for xx00 = 9*9*1*1 = 81, hence total zeros = 81*2 = 162
for x0x0 = 9*1*9*1 = 81, hence total zeros = 81*2 = 162
for x00x = 9*1*1*9 = 81, hence total zeros = 81*2 = 162
for xxx0 = 9*9*9*1 = 729, hence total zeros = 729*1 = 729
for xx0x = 9*9*1*9 = 729, hence total zeros = 729*1 = 729
for x0xx = 9*1*9*9 = 729, hence total zeros = 729*1 = 729
total zeros in four digit numbers = 27 + 3*162 + 3*729 = 2700
thus total zeros will be 0+9+180+2700+4 (last 4 is for 4 zeros of 10000)
= 2893

50.0 mL 0.0500 M calcium hydroxide, Ca(OH)2 (aq) has the highest pH value.

Sodium hydroxide and Calcium hydroxide are strong bases so they completely ionize in solution. Because they ionize at the same rate, and Calcium hydroxide has the higher pH calculated, then Calcium hydroxide, in fact, has the highest pH.

Nitric acid is a strong acid, so it completely ionizes in water. Whilst nitrous acid is a weak acid. Therefore, the nitric acid solution has the LOWEST ph.

If you read newspaper daily, then you may be aware of the four coloured dots on the corner of the newspaper. 

The four dots CMYK — blue (Cyan), pink (Magenta), Yellow and black (Kalio) are registration marks used during printing to help ensure the print is aligned properly. Any colour can be obtained by adding the correct proportion of these four colours.

CMYK is used as a base for the colours used in printing newspapers, and these four colours are often printed on the paper in either a heart, dot, or square shape.

To print an image, the plates of all these colours are laid out on a page separately and lined up in the same spot while printing. If those four dots are blur or you find the colours overlapping on the image it means the printing is not good. To print an accurate and perfect image, the colors and shape must be arranged precisely and must be claear sharp in order to get the best output.

That's why CMYK is also called registration mark. As physically checking all the pages of the paper is not possible for a printer who prints number of news papers daily, he just checks these dots.

Let Cost Price(C.P) = P
gain% = {(S.P-C.P)/C.P} x 100
25 = {(1540-P)/P} x 100
25/100 = (1540-P)/P
=> P = 4(1540)-4P
=> 5P = 4(1540)
=> P = 1232
So, Cost Price = Rs. 1232

The term computer is derivrd from the latin keyword 'computare' which means to calculate or to compute.

Let us assume S as number of shirts and T as number of trousers
Given that each trouser cost = Rs.70 and that of shirt = Rs.30
Therefore, 70 T + 30 S = 810
=> 7T + 3S = 81......(1)
T = ( 81 - 3S )/7

We need to find the least value of S which will make (81 - 3S) divisible by 7 to get maximum value of T
Simplifying by taking 3 as common factor i.e, 3(27-S) / 7
In the above equation least value of S as 6 so that 27- 3S becomes divisible by 7

Hence T = (81-3xS)/7 = (81-3x6)/7 = 63/7 = 9

Hence for S, put T in eq(1), we get
S = 81-7(9)/3 = 81-63 / 3 = 18/3 = 6.
The ratio of T:S = 9:6 = 3:2.

Total number of female members = 115

Let the number of males = x

Number of females = y

=> x + y = 115  ......(1)

According to the given data,

x + y(0.50) = 69 ......(2)

From (1) & (2), we get

0.5y = 46

=> y = 46 x 2 = 92

=> x = 115 - 92 = 23

Hence, required number of gentlemen in the family = x = 23.