25/50 = 1/2 soooooooooooooooooooooooooooooooooo
This year there are 900 rabbits which represents 200% of last year's population, means that last year the number of rabbits was:
x = 900 (100/200) = 450 rabbits.
The mathematical expression can be derived by a simple rule of three.
So, for last year the population was 450 rabbits.
Answer:
The value of y when x = 90
y = 22.5
Step-by-step explanation:
<u><em>Step(i)</em></u>:-
The value of y is directly proportional to the value of x.
Y∝ X
y = k x
If y = 45 when x = 180
45 = k ( 180)

<u><em>Step(ii):</em></u>-
The value of y when x = 90
y = 0.25 × 90 = 22.5
y = 22.5