Answer:
Step-by-step explanation:
Alright, lets get started.
The original photo size is 4 inches wide and 6 inches tall.
So, the ratio of width and height will be = 
The new enlarged photo will be of the same ratio means 2:3
The width of enlarged photo is given as 12 inches.
Suppose new height of enlarged photo is H, so

Cross multiplying

Dividing 2 in both sides
inches
So the height of new enlagred photo will be 18 inches. : Answer
Hope it will help :)