Find the power of a convex lens if the image formed is at a distance of 10 cm from the lens when the object is placed on the other side of the lens at 40 cm from the optical centre?
With which country has India signed an agreement for assistance in green and sustainable construction of infrastructure in the Himalayan Kingdom in December, 2016?
By increasing the price of entry ticket to a fair in the ratio 5:7, the number of visitors to the fair has decreased in the ratio 11:9. In what ratio has the total collection increased or decreased?