426.—­THE HYMN-BOARD POSER.

The worthy vicar of Chumpley St. Winifred is in great distress.  A little church difficulty has arisen that all the combined intelligence of the parish seems unable to surmount.  What this difficulty is I will state hereafter, but it may add to the interest of the problem if I first give a short account of the curious position that has been brought about.  It all has to do with the church hymn-boards, the plates of which have become so damaged that they have ceased to fulfil the purpose for which they were devised.  A generous parishioner has promised to pay for a new set of plates at a certain rate of cost; but strange as it may seem, no agreement can be come to as to what that cost should be.  The proposed maker of the plates has named a price which the donor declares to be absurd.  The good vicar thinks they are both wrong, so he asks the schoolmaster to work out the little sum.  But this individual declares that he can find no rule bearing on the subject in any of his arithmetic books.  An application having been made to the local medical practitioner, as a man of more than average intellect at Chumpley, he has assured the vicar that his practice is so heavy that he has not had time even to look at it, though his assistant whispers that the doctor has been sitting up unusually late for several nights past.  Widow Wilson has a smart son, who is reputed to have once won a prize for puzzle-solving.  He asserts that as he cannot find any solution to the problem it must have something to do with the squaring of the circle, the duplication of the cube, or the trisection of an angle; at any rate, he has never before seen a puzzle on the principle, and he gives it up.

[Illustration]

This was the state of affairs when the assistant curate (who, I should say, had frankly confessed from the first that a profound study of theology had knocked out of his head all the knowledge of mathematics he ever possessed) kindly sent me the puzzle.

A church has three hymn-boards, each to indicate the numbers of five different hymns to be sung at a service.  All the boards are in use at the same service.  The hymn-book contains 700 hymns.  A new set of numbers is required, and a kind parishioner offers to present a set painted on metal plates, but stipulates that only the smallest number of plates necessary shall be purchased.  The cost of each plate is to be 6d., and for the painting of each plate the charges are to be:  For one plate, 1s.; for two plates alike, 113/4d. each; for three plates alike, 111/2d. each, and so on, the charge being one farthing less per plate for each similarly painted plate.  Now, what should be the lowest cost?

Readers will note that they are required to use every legitimate and practical method of economy.  The illustration will make clear the nature of the three hymn-boards and plates.  The five hymns are here indicated by means of twelve plates.  These plates slide in separately at the back, and in the illustration there is room, of course, for three more plates.