Marco and his dad went strawberry picking. Together they collected strawberries that weighed w pounds. On the way back Marco ' dad lost x pounds of strawberries. Marco's strawberries now weighed y pounds. How much did his dad's strawberries weigh now?

1. Marco and his dad went strawberry picking. Together they collected strawberries that weighed w pounds. 
2. On the way back Marco's dad lost x pounds of strawberries. 
3. Marco's strawberries now weighed y pounds. 

Now we can answer the question. How much did his dad's strawberries weigh now? 

3. His dad's strawberries now weigh w-x pounds.