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Abedket s in tre toofsis in the form of a frustrum of a cone of height is 30 cm with radi ofoffgits lower and upper ends as 10 cm and 20 cm respectively Find the capacitythe bucket, Aiso, find the cost of milk which can completely fill the containeratthe rate ofRu 25 per liter(Take %-314) 5yq("Oo-. A jar contains 24 marbles, some are green and others are blue. If a marble is |
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Answer» Solution:- Radius of the upper end of the frustum of cone = R = 20 cmradius of the lower end of the frustum of cone = r = 10 cmH = 30 cmVolume = 1/3πh[R² + r² + R*r]= 1/3*22/7*30*[20² + 10² + 20*10]= 660/21*[400 + 100 + 200]= (660*700)/21= 22000 cu cm or capacity = 22 litersNow, Slant height 'l' =√(R - r)² + h²l =√(20 - 10)² + 30²l =√10² + 30²l =√1000l = 31.62 cmSlant height is 31.62 cmSurface area =πR² +πr² +π(R + r)l=π[R² + r² + (R + r)*l]= 22/7*[20² + 10² + (20 + 10)*30]= 22/7*[400 + 100 + 30*30]= (22*1400)/7Surface area = 4400 sq cmCost of 1 liter milk = Rs. 25Total cost of 22 liter milk = 22*25=Rs 550 |
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