Answer:
50%
Step-by-step explanation:
The mother's genes are aa, and the father's genes are Aa. When you do the punnett square you get the following in the square:
Aa aa
Aa aa
The only way a child will have attached earlobes is to be aa. There are 2 possibilities out of 4 total. 2/4 = 50%. Thus for a child to have attached earlobes is 50%