A farmer has a basket of apples. Counting them by 2s leaves 1 extra. Counting by 3s leaves 1 extra. Counting by 5s leaves 1 extra. Counting by 7s leaves none extra. What is the smallest total number of apples he could have?
91
The number minus 1 must be divisible by 2, 3, and 5 (hence a multiple of 30). Test multiples of 30 plus 1: 31, 61, 91. 91 is the first number in this sequence divisible by 7 (91 / 7 = 13).
About this riddle
Math riddles hide a calculation inside a short story. Pull out the numbers, work out what is being asked, and watch for a trick such as a unit change.
Difficulty: Hard. More like this: Math riddles with answers or try Target 24 for a different kind of puzzle.
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