Fiji number quiz

[Pea Brain]

Please could someone kindly help me with clues for a few of these questions :-
24. But could be over fifty
49. A problem for Ms Christie
69. Decrease in squalid surroundings
79. (I presume these are mathematical symbols ?)
91. A 50mph wind for an old ISP
Many thanks in advance. P

[Ternigapp]

49. Agatha Christie novel

[gen2]

24 is an anagram

[gen2]

Decrease is what you do to your clothes after the wash.

[Pea Brain]

Many thanks for those helpful clues though Im not sure where the squalid surroundings come into it !!!! Any chance of a clue for the other two ? !!! P

[dd47]

No 79. Look for numbers under the rising sun.
no 91. Look at the Beaufort scale,
and don't blame the pigs for the squalid surroundings.

[poodledoo]

There are several Agatha Christie novels with numbers in the title. Which one are we supposed to choose?

[Pea Brain]

Poodledoo. I chose the one that also had problem in the title !!! Many thanks dd47. P