Q: How much is 50 minus 40? A: 
Q: How much is 41 minus 23? A: 
Q: How much is 56 minus 40? A: 
Q: How much is 50 minus 40? A: 
Q: How much is 50 minus 40? A: 
Q: How much is 50 minus 20? A: 
Q: How much is 51 minus 44? A: 
Q: How much is 50 minus 40? A: 