(1)设他们一共去了x个成人,则有(12-x)个学生,
由题意得,35x+35×0.5×(12-x)=350,
解得:x=8,12-x=12-8=4,
答:他们一共去了8个成人,4个学生;
(2)由题意,得35×16×a 10 =350-14,
解得:a=6.
答:a的值为6.
(1)设他们一共去了x个成人,则有(12-x)个学生,
由题意得,35x+35×0.5×(12-x)=350,
解得:x=8,12-x=12-8=4,
答:他们一共去了8个成人,4个学生;
(2)由题意,得35×16×a 10 =350-14,
解得:a=6.
答:a的值为6.