Answer:12 members of the track team do both the hurdles and the long jump.
Explanation:
As there are 40 members on the track team, if 3/8 of them do the hurdles, we have to divide 40 by 8 and the multiply the result by 3 to know the number. So, 40 / 8 is 5, and 5 x 3 is 15. Therefore, 15 members do the hurdles.
Of the members who do the hurdles, 4/5 of them also do the long jump. Using the same method, as 15 / 5 is 3, and 3 x 4 is 12, 12 members of the track team do both the hurdles and the long jump.