Two students make a model of a tree house they want to build. The scale is 1:42. In the scale model, the door is 3 cm tall. How tall should the real tree house door be?

The real tree house door should be 126 cm tall.

Explanation:

Given: Two students make a model of a tree house they want to build. The scale is 1:42.

i.e. 1 cm of model = 42 cm in real

if the in the scale model,the door is 3 cm tall, then the height of real tree house door  = 3  x (42) cm

⇒ Height of real tree house door=  126 cm

Hence, the real tree house door should be 126 cm tall.

the awnser is a

it is not b or c