Dillesh4096
In a city there were 600 restaurants which make at least one the three food items out of Chinese, Continental and South Indian. The number of restaurants who make only Continental were 4 times of those who make only South Indian. The number of restaurants who make only Continental and Chinese were 1/5 of those who make only Chinese. The number of restaurants who make only Chinese were 3/4 times of those who make only continental. If 220 restaurants make South Indian, how many make Continental and Chinese only?
A. 10
B. 20
C. 30
D. 35
E. 73
Solution:Since there are 600 restaurants in total and 220 restaurants make South Indian, 600 - 220 = 380 restaurants make Chinese or Continental. So:
380 = Only Chinese + Only Continental + Only Chinese and Continental
Let x = the number of restaurants that make only Chinese and Continental. Since the number of restaurants who make only Continental and Chinese are 1/5 of those who make only Chinese, the number of restaurants that make only Chinese is 5x. Further, we are told that the number of restaurants who make only Chinese were 3/4 times of those who make only continental; thus:
Only Chinese = 3/4 * Only continental
5x = 3/4 * Only continental
Only continental = 5x / (3/4) = 5x * 4/3 = 20x/3
Now, we can calculate the value of x:
380 = Only Chinese + Only Continental + Only Chinese and Continental
380 = 5x + 20x/3 + x
380 = 15x/3 + 20x/3 + 3x/3 = 38x/3
x = 380 * 3/38 = 30
So, there are x = 30 restaurants that make only Chinese and Continental.
Answer: CNote: We did not have to use the fact that “The number of restaurants who make only Continental were 4 times of those who make only South Indian.”