The average weight of 45 passengers in a bus is 52 kg. 5 of them whose average weight is 48 kg leave the bus and other 5 passengers whose average weight is 54 kg join the bus at the same stop. What is the new average weight of the bus?

? ( 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