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A metallic right circular cone 20 cm high and whose vertical angle is 60° is cut into two parts at the middle of its height by a plane parallel to its base. If the frustum so obtained is drawn into a wire of diameter 1/16 cm, find the length of the wire.

Solution From ΔAEG \(\begin{array}{l}\frac{EG}{AG}=\tan 30\end{array} \) \(\begin{array}{l}\frac{10}{\sqrt{3}}=EG\Rightarrow EG=\frac{10\sqrt{3}}{3}\end{array} \) From ΔAEG \(\begin{array}{l}\frac{BD}{AD}=\tan 30\end{array} \) \(\begin{array}{l}BD=\frac{20}{\sqrt{3}}=\frac{20\sqrt{3}}{3}\end{array} \) Radius (r1) of upper end of... View Article

An organisation selected 2400 families at random and surveyed them to determine a relationship between income level and the number of vehicles in a family. The information gathered is listed in the table below: Suppose a family is chosen. Find the probability that the family chosen is (i) earning Rs. 10000 – 13000 per month and owning exactly 2 vehicles. (ii) earning Rs. 16000 or more per month and owning exactly 1 vehicle. (iii) earning less than Rs. 7000 per month and does not own any vehicle. (iv) earning Rs. 13000 – 16000 per month and owning more than 2 vehicles. (v) owning not more than 1 vehicle.

Monthly income (in ₹) Vehicles per family 0 1 2 Above 2 Less than 7000 10 160 25 0 7000-10000... View Article