A bank charges simple interest for ₹K at the rate of r² for n² years. Another bank charges simple interest for ₹L at the rate of r³ for n³ years and gives the same interest. The ratio between K and L is:
Two circles touch each other externally as shown in the figure above. The radius of the circle with centre O is 49 cm. The radius of the circle with centre A is 16 cm. Find the length (in cm) of their common tangent BC.