$$(175-150)\times 10 = 250$$. 
A shop purchased some tennis rackets at ＄$$150$$ each. It then sold them at ＄$$175$$ each. How much did the shopkeeper earn for $$10$$ rackets? 
Options:
[a] ＄$$150$$ 
[b] ＄$$200$$ 
[c] ＄$$250$$ 
[d] ＄$$300$$ 