In a class of 100 students, the number of students passed in English only is 46, in Maths only is 46, in Commerce only is 58. The number who passed in English and Maths is 16, Maths and Commerce is 24 and English and Commerce is 26, and the number who passed in all the subjects is 7. Find the number of the students who failed in all the subjects.

? ( 22 x r²) / 7 = 38.5
? r² =(38.5 x 7) /22
? r = 3.5 cm

? Circumference = 2 x (22/7) x 3.5 cm
= 22 cm

S.P = P.W of Rs. 2200 due 1yr hence = Rs. [(2200 x 100)/100+(10 x 1)] = Rs.2000 

Gain = Rs.(2000-1950) = Rs. 50

PW =  A m o u n t 1 + R 100 T = 2800 1 + 12 100 2   = Rs.2500 

TD = Amount - PW = 2800 - 2500 = Rs.300

P.W. = Rs. (1600 - 160) = Rs. 1440
? S.I. on Rs.1440 at 5% is Rs. 160.
? Time = [100 * 160 / 1440 * 5] = 20/9 years = [20/9 * 12] months = 27 months.

? s= (13 + 5 + 12) / 2 cm
= 15cm

s-a = 2 cm,
s-b = 10 cm and
s-c = 3 cm

? Area = ? (15 x 2 x 10 x 3 ) cm²
= 30 cm²

? (12 x h) / 2 = 30
? h = 5 cm

Let lateral side = (5y) cm and base = (4y) cm
? perimeter = 5y + 5y + 4y = 14
?y = 1

So, the sides are 5 cm , 5 cm and 4 cm

Now s= 1/2 (5 + 5 + 4) cm = 7 cm
(s-a) = 2 cm
(s-b) = 2 cm and
(s-c) = 3 cm

? Required Area = ? (7 x 2 x 2 x 3) cm²

=2?21 cm²

s = (13 + 14 + 15 ) / 2 = 21,
s-a = 8 ,
s-b = 7,
s-c= 6

? Area to be painted = ? [s(s-a) (s-b) (s-c)]
=? [21 x 8 x 7 x 6] m²
= 84 m²

? Cost of painting = Rs. (84 x 8.75) = Rs. 735

Area = ?r² = 0.49?
? r = 0.7 m

Number of revolutions = total distance / circumference
= (1.76 x 1000) / (2 x 22/7 x 0.7)
= 400

Distance travelled in 1 revolution = circumference of the wheel
= ?d
= ( 22/7 ) x 63
= 198 cm

So the distance travelled in 100 revolutions = 100 x distance travelled in 1 revolution
= 100 x 198 cm
= 19800 cm
= 198 m

Circumference of a circular = 2?r
? 2 x (22 / 7) x r = 440
? r = [440 x (7/22) x (1/2)] = 70 m

? Radius of outer circle = (70 + 14) m
= 84 m