Mr. Sim has some pens. If he ties them in bundles of 7, he will have 3 extra pens. If he ties them in bundles of 9, he would be short of 4 pens. What is the smallest possible number of pens Mr. Sim has?
Multiples of 7: 7, 14, 21, 28, 35, 42, 49, 56
Multiples of 7 (+3): 10, 17, 24, 31, 38, 45, 52, 59
Multiples of 9: 9, 18, 27, 36, 45, 54, 63
Multiples of 9 (-4): 5, 14, 23, 32, 41, 50, 59
Smallest possible number of pens that Mr. Sim has = 59
Answer(s): 59
