Answer:
To calculate the total material needed for the four dresses, we need to consider the material requirements for each dress separately and then sum them up.
Dress for a 7-year-old:
Material needed = 2.5 meters
Dresses for two 4-year-olds:
Material needed for each 4-year-old = 2 meters
Total material needed for two 4-year-olds = 2 * 2 = 4 meters
Dress for a 10-year-old:
Material needed = 3 meters
Now, let's add up the material needed for all four dresses:
Total material needed = Material for 7-year-old dress + Material for two 4-year-olds' dresses + Material for 10-year-old dress
=
2.5
meters
+
4
meters
+
3
meters
=2.5 meters+4 meters+3 meters
=
9.5
meters
=9.5 meters
So, a total of 9.5 meters of material will be needed to make the four dresses.
