Arun took a loan of Rs. 29000 with simple interest for as many years as the rate of interest. If he paid Rs. 10440 as interest at the end of the loan period, what was the rate of interest?

? ( 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