Question

In the figure 7.12, a cylindrical wrapper of flat tablets is shown. The radius of a tablet is 7 mm and its thickness is 5 mm. How many such tablets are wrapped in the wrapper ?

Answer 1

SOLUTION:-
GIVEN BY:-
radius of tablet (r) = 7mm
thickness (h)= 5mm
volume of tablet =
$\pi {r}^{2} h \\ = \pi \times {7}^{2} \times 5 \\ = 49 \times 5\pi \\ = 245 \times \frac{22}{7} \\ = 770 {mm}^{3}$
Radius of wrapper( R ) = 14/2 = 7mm
thikness of wraper (H) = 10cm = 100mm
Volume of wraper(V) =
$\pi \: {R}^{2} H \\ = \frac{22}{7} \times {7}^{2} \times 100 \\ = 22 \times 7 \times 100 \\ =15 4 \times 1 00 \\ = 15400 {mm}^{3}$
we get , tablets are wrapped in the wrapper
= 15400/770
= (20) ans

■I HOPE ITS HELP■

Answer 2

Given height = 10 cm.

Given radius of a tablet = 7 mm

= 7 * 0.1 cm

= 0.7 cm.

Given thickness = 5 mm

= 0.5 cm.

We know that Volume of the wrapper = pir^2h

= (22/7) * (0.7)^2 * (10)

= 22 * 0.07 * 10

= 15.4.

Then,

Volume of the one tablet = (22/7) * (0.7)^2 * 0.5

= 22 * 0.07 * 0.5

= 0.77.

Therefore, the number of tablets wrapped in the wrapper = (15.4)/0.77

= 20.

Hope it helps!