Hint
As we don't know how of the people were library members, you can try a random number and see what happens.
Answer
4,200 books.
Reasoning
It doesn't matter how many library members there were, as 1/2 of them accepted the books, and each accepted 6 books, which is 3 books per member on average.
Similarly, it doesn't matter how many non-members there were as 3/4 of them accepted the books, and each accepted 4 books, which is again 3 books per non-member on average.
Double-Checking
Both the members and non-members accepted, on average, 3 books each.
And 1400 x 3 = 4200.
??
Puzzle 58
Using the letters AAEENNPPPPSS complete this grid. The grid reads the same across and down.
S
A
E
T
Note: this puzzle is not interactive, and the squares cannot be clicked.
Below, 10 nine-letter words have been broken into chunks of three letters.
The chunks have been moved around, no chunk is used twice, and all of the chunks are used.
Can you determine what the 10 words are?
rbr ent ard man tor rbo
and ban con erf dst dli
fly spa dra dif hai ght
per all fis ove ush hea
new gon fer wat her duc
Hint
The first letters of the words are: W, O, B, H, D, F, C, N, H, D.
Answers
wat + erf + all = waterfall
ove + rbo + ard = overboard
ban + dst + and = bandstand
hai + rbr + ush = hairbrush
dif + fer + ent = different
fis + her + man = fisherman
con + duc + tor = conductor
new + spa + per = newspaper
hea + dli + ght = headlight
dra + gon + fly = dragonfly
??
Puzzle 60
We have been quite lucky with the weather recently, it has got steadily warmer each day, over the last five days.
By this, I mean that the temperature rose by the same amount each day.
The average temperature was 2 °C, and I know it froze on two occasions (0 °C).
I also know the product of the temperatures was over 500 but below 2,000 and each temperature was an integer.
Hint
What must the middle temperature be? Remember that the temperature are in degrees Celsius.
Answer
The temperatures were -6, -2, 2, 6, 10 °C.
Each day increased by a steady 4 degrees.
Reasoning
As the temperature rose steadily each day, we know that the middle temperature (Day 3) was 2 degrees (because the average was 2 degrees).
Since Day 3 was 2 degrees, and there were two negative temperatures, we know that the daily increase must have been at least 3 degrees (otherwise Day 2 would not have been negative).
If we check a daily increase of 3 degrees, the sequence would be -4, -1, 2, 5, 8, but this doesn't work as the product is less than 500.
If we check a daily increase of 4 degrees, the sequence would be -6, -2, 2, 6, 10, which does matches all of the requirements.
If we check a daily increase of 5 degrees, the sequence would be -8, -3, 2, 7, 12, but this doesn't work as the product is more than 2000.
Any larger increase makes the product even larger, so we can stop checking.
