Using each of the nine digits 1 to 9 exactly once, some in the numerator and the rest in the denominator, write a fraction equal to 21. Then do the same for 31, 41, 51, 61, 71, 81 and 91.
Solution
One solution for each, though there are others: 215181=134586729,=134852697,=254963187,316191=174965832,=176582943,=574296381.4171=157683942,=167582394, In each, the four-digit numerator times the whole number on the left gives the five-digit denominator, and between numerator and denominator the digits 1 to 9 each appear once. For instance 6729×2=13458 and 6381×9=57429.