True or false: Constable created hundreds of thumbnail sketches before beginning a final piece

How does the image distance (di) of a convex lens compare with the image distance of a concave lens? a. the image distance of the convex lens is positive, and that of the concave lens is negative. b. both are negative for a virtual image. c. both are positive for a virtual image d. the image distance of the convex lens is negative, and that of the concave lens is positive.

Could someone . i have tried to solve myself but my calculation is off

Individuals who live below the poverty line get seriously ill more often than those who do not what could be the hidden variable in this situation?