April has 30 days, so if he didn't walk the dog on Sundays, he worked for a total of 30 days - 4 days = <<30-4=26>>26 days.

If each day he earned $10, he ends up with 26 days * $10/day = $<<26*10=260>>260 .

After buying books and giving his sister $50, he ends up with $260 - $50 - $50 = $<<260-50-50=160>>160

# Answer

160
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
John's neighbor tells him to walk his dog for 1 hour each day for a total of $10. He does this for April, save for the 4 Sundays in April. He later spent $50 on books and gave his sister Kaylee the same amount. How much money did John have left?
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
160
John's neighbor tells him to walk his dog for 1 hour each day for a total of $10. He does this for April, save for the 4 Sundays in April. He later spent $50 on books and gave his sister Kaylee the same amount. How much money did John have left?
train