Q: How much is 16 minus 15? A: 
Q: How much is 97 minus 10? A: 
Q: How much is 17 minus 15? A: 
Q: How much is 16 minus 10? A: 
Q: How much is 86 minus 15? A: 
Q: How much is 16 minus 15? A: 
Q: How much is 20 minus 19? A: 
Q: How much is 16 minus 15? A: 