Lucia is not yet 80 years old. each of her sons has as many sons as brothers. the combined number of lucias sons and grandsons equals her age, and her oldest grandson is 29. how old is lucia? place your numerical answer in the corresponding answer blank.

Exits on an interstate are numbered consecutively. the distance between exit 12 and exit 13 is 2.7 miles. the distance between exit 13 and exit 14 is 0.9 mile farther than the distance between exit 12 and exit 13. the distance between exit 13 and exit 15 is 6.8 miles farther than the distance between exit 12 and exit 14. the distance between exit 14 and exit 15 is miles.