Question

in a temple there are 15 cylindrical pillars the diameter of each pillar is 18 cm and height is 4.9 m
and find the cost of painting each a pillar at the rate of ₹20 per metre square

Answer 1

Total cost:- 831.6 rs
"" "" "" "" "" "" "" "" "" ""

Answer 2

$given \: that \: d = 18cm$

$so \: radius = \frac{d}{2} = \frac{18}{2} = 9cm$

$converting \: cm \: to \: m \: we \: get \:$

$= \frac{9}{100} = 0.09m$

$height = 4.9m$

$csa = 2\pi \: rh \:$

$= 2 \times \frac{22}{7} \times 0.09 \times 4.9$

$= 2.772$

$cost \: of \: painting \: one \: pillar = 2.772 \times 20 = rupees55.44$

$since \: there \: are \: 15 \: such \: pillar$

$total \: area \: to \: be \: painted = 2.772 \times 15 = 41.52 {m}^{2}$

$hence \: total \: cost \: = 20 \times 41.58 = rupees831.60$

please follow me friend !!