Explanation:
1)
to finish the work in 30 days, 9 workers are needed.
that means one worker can do 1/9 of the work in 30 days, and therefore 1/9 / 30 = 1/270 of the work in one day.
that means we need 270 workdays to finish the work.
to get the work done in 18 days we need therefore
270/18 = 15 workers
2)
you mention only 3 things (emergency, Tracey insurance and mutual fund) but the ratio covers 4.
what is missing ?
without that information this cannot be solved.
but this is what you do, when you find the 4th thing :
the ratio 9 : 5 : 4 : 7 tells us that the whole (P5000) is split into 9+5+4+7 = 25 parts.
each part is therefore worth 5000/25 = P200.
so, whatever is represented by 9 parts gets 9×200 = P1800.
whatever is represented by 5 parts gets 5×200 = P1000.
whatever is represented by 4 parts gets 4×200 = P800.
and whatever is represented by 7 parts gets 7×200 = P1400.