What is the primary benefit for people and nations that engage in trade?

 a country may be able to benefit from buying products from a foreign country.  The product may not be available in their own country or the other country may have a comparative advantage in producing it.  Either way, importing these products benefits a country.

$1.40 * 0.8=1.12. 1.4+1.12=1.52. 1.52*0.25=$1.14. Your answer is $1.14.