Answer:
40cm
Step-by-step explanation:
set up a proportion of width to height.
10/16 = 25/x
cross multiply to get 10x = 400
solve for x and get 40 cm
check your answer by seeing that the poster width (25) is 2.5 x larger than the photograph width (10). the height should have the same ratio, so 16 x 2.5, does indeed = 40.
