Tangents ^@ PA ^@ and ^@ PB ^@ are drawn from an external point ^@ P ^@ to two concentric circles with centre ^@ O ^@ and radii ^@ 7 \space cm ^@ and ^@ 4 \space cm ^@ respectively. If ^@ AP = 8 \space cm ^@, what the length of ^@ BP ^@ ?
A metal piece is consists of a right circular cylinder and cone as shown in the picture. The radius of cone and cylinder is 4 cm. The height of cylinder and cone are 18 cm and 9 cm respectively. If density of metal is 10 grams per cm3, find the weight of metal piece. (Assume π =