Answer:
660 exchanges
Step-by-step explanation:
Number of relatives = 12
Number of years = 5
Since each relative gives gift to one another each year:
Then each relative hands out 11 gifts (person giving out the gift will not be counted) to the others, and others also do the same.
Therefore, yearly exchange :
(Number of relatives * number of gifts given out per person)
(12 × 11) = 132
Number of exchanges after 5 years :
(Number of yearly exchanges × number of years)
(132 × 5) = 660