Question 30520
M+J=16 7 YEARS AGO THEREFORE TODAY THEY ARE EACH 7 YEARS OLDER  THUS THEIR COMBINED AGE IS NOW 16+7+7 OR 30.

NOW M=2J THUS M+2M=30 OR 3M=30 OR M=10 & J=20.

MARY IS NOW 10 JABE IS NOW 20.

MARY 7 YEARS AGO WAS 3 JABE 7 YEARS AGO WAS 13.