TNPSC G2 Previous Year Question Papers General Studies - 2017

Explanation:

Area of semi-circle =$\dfrac{\pi r^{2}}{2}=\dfrac{1}{2}\times\dfrac{22}{7}\times7\times7$

$=77cm^{2}$

Explanation:

Take x as common ,$\dfrac{x(x-2)\times3(x+2)}{x(x+2)\times(x-2)}=3$

Explanation:
The Boy's age = A
The Sister's age = B
A boy is now twice as old as his sister A=2B
Four years ago, he was thrice as old as her
(A-4) = 3(B-4)
apply A = 2B
2B-4 = 3B-12
3B-2B = 12-4
B=8
A= 2B
A=2(8)
A=16
Boy's age=16 years
Sister's age=8 years

Explanation:

$\dfrac{x^{\dfrac{3}{2}}}{9}=\dfrac{16}{x^{\dfrac{1}{2}}}$

$x^{\dfrac{3}{2}+\dfrac{1}{2}}=16\times9$

$x^{2}=16\times9$

$x=4\times3=12$

Explanation:

Let R ans r be the outer and inner radii of the hemisphere.

Now,its curved surface area=outer surface area+inner surface area

$2R^{2}\times2r^{2}$

$=2\pi (R^{2}+r^{2})sq.units$

$Total surface area=outer surface area+inner surface area+Area at the base$

$=2\pi R^{2}+2\pi r^{2}+\pi (R^{2}-r^{2})$

$=2\pi (R^{2}+r^{2})+\pi(R+r)(R-r)sq.units$

$=\pi(3R^{2}+r^{2})sq.units$

Explanation:
There is 366 days In leap year
Now
52 weeks * 7 days/week = 364 day
52 full weeks means -> 52 Friday
For remaining 2 days, one of the following pair is possible
(sun,Mon) (Mon,Tue) (Tue,Wed) (Wed,Thu) (Thu,Fri) (Fri,Sat) (Sat,Sun)
Out of 7 pair there is 2 pair in which 53rd Friday may come.
Probability of 53 Friday in a leap year = (Thu,Fri) (Fri,Sat) = 2/7
Out of 7 pair there is 2 pair in which 53rd Saturday may come.
Probability of 53 Saturday in a leap year = (Fri,Sat) (Sat,Sun) = 2/7

$p(AUB)=p(A)+p(B)-p(AnB)$

$\dfrac{2}{7}+\dfrac{2}{7}-\dfrac{1}{7}=\dfrac{3}{7}$

Explanation:
$\left(x+y\right)^2+9\left(x+y\right)+8$
$=\left(\left(x+y\right)^2+\left(x+y\right)\right)+\left(8\left(x+y\right)+8\right)$
$=\left(x+y\right)\left(\left(x+y\right)+1\right)+8\left(\left(x+y\right)+1\right)$
$=\left(\left(x+y\right)+1\right)\left(\left(x+y\right)+8\right)$
$=\left(x+y+1\right)\left(x+y+8\right)$

Explanation:

$sum of first `n' odd nos=n^{2}$

$sum of first `n' natural nos=\dfrac{n(n+1)}{2}$

$Difference =n^{2}-[\dfrac{n^{2}+n}{2}]^{2}$

$=\dfrac{2 n^{2}-n^{2}-n}{2}$

$=\dfrac{n^{2}-n}{2}$

$=\dfrac{n(n-1)}{2}$

Explanation:
From given options we have to find the answer for this type of questions.
25% of 8=$\dfrac{25}{100}\times 8=2.0$
40% of 6=$\dfrac{40}{100}\times 6=2.4$
30% of 9=$\dfrac{30}{100}\times 9=2.7$
20% of 15 =$\dfrac{20}{100}\times 15=3.0$

Explanation:

$a.Area=\frac{1}{2}bh$

$ =\frac{1}{2}\times10\times8$

$=40c m^{2}$

$b.Right angled tiangle=13^{2}=5^{2}+12^{2}$

$ =\frac{1}{2}\times5\times12$

$ =30cm^{2}$

$c.Equilateral triangle=\frac{\sqrt{3}}{4}\times10\times10$

$ =25\sqrt{3}$

$ =25\times1.732$

$=43.3cm^{2}$

$d.Right angled triangle= \frac{1}{2}\times3\times4$

$ =6ccm^{2}$

Explanation:

Difference=53-43=10 should be increase

New average=27+$\dfrac{10}{75}$

= 27.13

Explanation:

n=3 times

$N=\dfrac{(n-1)\times100)}{R}$

$ =\dfrac{(3-1)\times100}{8}$

$ =\dfrac{200}{8}$

$ =25 years$