Question

the two owners A and B cell flavoured milk filled to capacity in mom of negligible thickness which are cylindrical in shape with raised hemispherical bottom the marks are 14 cm high and have diameter of 7 cm as shown in given figure both A and B cell flavoured milk at rupees 80 per litre. the dairy owner is is the formula of πr2h to find the volume of milk in the month charges rupees 43.12 for it dary on FB is of the view that the price of actual quantity of milk should be charged.what according to him should be the price of one mug of milk? which value is exhibited by the dairy owner B? ( use π = 22/7)

Answer 1

we know that 
1 dm = 1 litre

according to question
radius    r = 0.7/2 dm
and Height    h = 1.4 dm
thus

Volume of mug = pi r^2 h - 2/3 pi r^3
                          = pi r^2  (h - 2/3 r)
                         = 22/7 * 0.49/2  (1.4 - 1.4/6)
                        = 0.898  lit

Cost of 1 lit milk    = Rs 80
So cost of 0.898 lit     = 80 * 0.898
                                   = 71.86 Rs

Answer 2

Capacity of mug (Actual quantity of milk) = πr2h - 2/3 πr3

= πr2(h - 2r/3)

r = 7/2 and h = 14

Capacity of mug = 2695/6 cm3

Amount dairy owner B should charge for one mug of milk

= 2695/6 × 80/1000

= Rs. 35.93