Compute.
6 yr 7 months+ 2 yr 11 months
A8yr 18 months
B9 yr 5 months
.c. 9 yr 6 months
D8 yr 6 months
6 yr 7 months+ 2 yr 11 months
A8yr 18 months
B9 yr 5 months
D8 yr 6 months