Barbara has more than 50 but less than 60 mochi balls. If she puts them equally into packets of 5, she would be short of 1 mochi balls. If she puts them equally into packets of 7, she would have 3 extra mochi balls. How many mochi balls does Barbara have?
Multiples of 5: 40, 45, 50, 55, 60, 65
Multiples of 5 (-1): 39, 44, 49, 54, 59, 64
Multiples of 7: 42, 49, 56, 63
Multiples of 7 (+3): 45, 52, 59, 66
Common number more than 50 but less than 60: 59
Number of mochi balls that Barbara has = 59
Answer(s): 59