, we get 10 pictures marked thus:--

x x x x x x x x x (x)
x x x x (x)
x x (x)

By then assigning o's in the same way, beginning at the other end, we
get 9 pictures marked thus:--

(o) o
(o) o o o
(o) o o o o o o o o

All we have now to do is to run these two wedges as close together as
they will go, so as to get the minimum number of pictures----erasing
optional marks where by so doing we can run them closer, but otherwise
letting them stand. There are 10 necessary marks in the 1st row, and in
the 3rd; but only 7 in the 2nd. Hence we erase all optional marks in the
1st and 3rd rows, but let them stand in the 2nd.

* * * * *

Twenty-two answers have been received. Of these 11 give no working; so,
in accordance with what I announced in my last review of answers, I
leave them unnamed, merely mentioning that 5 are right and 6 wrong.

Of the eleven answers with which some working is supplied, 3 are wrong.
C. H. begins with the rash assertion that under the given conditions
"the sum is impossible. For," he or she adds (these initialed
correspondents are dismally vague beings to deal with: perhaps "it"
would be a better pronoun), "10 is the least possible number of
pictures" (granted): "therefore we must either give 2 x's to 6, or 2 o's
to 5." Why "must," oh alphabetical phantom? It is nowhere ordained that
every picture "must" have 3 marks! FIFEE sends a folio page of solution,
which deserved a better fate: she offers 3 answers, in each of which 10
pictures are marked, with 30 marks; in one she gives 2 x's to 6
pictures; in another to 7; in the 3rd she gives 2 o's to 5; thus in
every case ignoring the conditions. (I pause to remark that the
condition "2 x's to 4 or 5 pictures" can only mean "_either_ to 4 _or
else_ to 5": if, as one competitor holds, it might mean _any_ number not
less than 4, the words "_or_ 5" would be superfluous.) I. E. A. (I am
happy to say that none of these bloodless phantoms appear this time in
the class-list. Is it IDEA with the "D" left out?) gives 2 x's to 6
pictures. She then takes me to task for using the word "ought" instead
of "nought." No doubt, to one who thus rebels against the rules laid
down for her guidance, the word must be distasteful. But does not I. E.
A. remember the parallel case of "adder"? That creature was originally
"a nadder": then the two words took to bandying