physics
posted by Chan .
Please, anyone help me please.
Q: An object is placed 17.8 cm from a first converging lens of focal length 13 cm. A second converging lens with focal length 24 cm is placed 10 cm to the right of the first converging lens. (Take the direction to the right to be positive.)
(a) Find the position q1 of the image formed by the first converging lens.
so, this what I try but, it not right
1/f2=1/q1+1/p1= 1/131/17.8=5/234, 234/5= 47cm and it not right answer.

Of course it is not right.
Draw a figure. Solve the image location for the first lens, then using that image location as the object location of the second lens, solve for the final image location.
A ray diagram probably will help you keep the numbers realistic. 
divide