From the question, we are informed that in a village the number of houses and the number of flats are in the ratio 9:5 while the number of flats and the number of bungalows are in the ratio 10:3 and that there are 30 bungalows in the village.
Since the ratio of the number of flats and the number of bungalows are in the ratio 10:3 and there are 30 bungalows in the village, the number of flats will be:
= 10/3 × 30
= 10 × 10
= 100 flats
Since we are told that the ratio of the number of houses to the number of flats are in the ratio 9:5 and we've gotten the number of flats as 100, then the number of houses will be:
I am not sure if I am right, but in my opinion, it is a valid sample, since they are participating and getting paid, so I would personally go for the third option, but the decision is on you.
