There are two correct answers to this math word problem.
The first one is grouping by type of fruit and irrelevant which particular orange, banana, or apple. Since you must have one of each, one of each gets removed.
You must then have 2 picks from 3 oranges, 2 bananas, and an apple.
Since only 2 picks, it is also the same as 2 oranges, 2 bananas, and 1 apple.
That gets you to an answer of "5"
o o o b a 3 oranges, 1 banana, 1 apple
o b o b a 2 oranges, 2 bananas and 1 apple
o a o b a 2 oranges, 1 banana, and 2 apples
b b o b a 1 orange, 3 bananas, and 1 apple
b a o b a 1 orange, 2 bananas, and 2 apples
However, if each piece of fruit is unique, and that is a "selection" the choices are much higher and the combinations is correct.
There are 157 selections of unique fruit pieces with at least one of each type.
Oranges 1-2-3-4-5, Bananas 6-7-8, apples 9-0
01236, 01237, 01238, 01246, 01247, 01248, 01256, 01257, 01258, 01267, 01268, 01269, 01278, 01279, 01289, 01346, 01367, 01368, 01369, 01378, 01379, 01389, 01467, 01468, 01469, 01478, 01479, 01489, 01567, 01568, 01569, 01578, 01579, 01589, 01678, 01679, 01689, 01789, 02347, 02348, 02356, 02357, 02358, 02367, 02368, 02369, 02378, 02379, 02389, 02456, 02457, 02458, 02467, 02468, 02469, 02478, 02479, 02489, 02567, 02568, 02569, 02578, 02579, 02589, 02678, 02679, 02689, 02789, 03456, 03457, 03458, 03467, 03468, 03469, 03478, 03479, 03489, 03567, 03568, 03569, 03578, 03579, 03589, 03678, 03679, 03689, 03789, 04567, 04568, 04569, 04578, 04579, 04589, 04678, 04679, 04689, 04789, 05678, 05679, 05689, 05789, 12369, 12379, 12389, 12469, 12479, 12489, 12569, 12579, 12589, 12679, 12689, 12789, 13679, 13689, 13789, 14679, 14689, 14789, 15679, 15689, 15789, 16789, 23469, 23479, 23489, 23569, 23579, 23589, 23679, 23689, 23789, 24569, 24579, 24589, 24679, 24689, 24789, 25679, 25689, 25789, 26789, 34569, 34579, 34589, 34679, 34689, 34789, 35679, 35689, 35789, 36789, 45679, 45689, 45789, 46789, 56789