what were 3 types of people that live in ancient India. This is for Social Science and I really need help.

Simple astronomical telescope the objective lens has a focal length of 75 cm and that of a piece of 5cm of the lenses are 18 cm apart when will be final image of a distant object before

The graph below plots the temperature and luminosity of stars on the main sequence.

Zac wanted to determine the measure of r and of ? r in the triangle below. to fine the measure of r, zac sets up the problem.42^2 + 24^2 = r 2. determine whether zac set the problem up correctly.