Although the above posts understood the answer to be E, with the current method, a slight variation in the values of the edges of the aquarium will lead to the wrong answer. Let me explain to you the solution and then will point out my findings.
Given Info:The question tells us that a rectangular aquarium has 36 sq. cm of water surface area per fish and we are asked to find the no. of fishes in the aquarium.
Interpreting the Given Info:Let’s interpret the question statement first. Let’s assume the no. of fishes in the aquarium be ‘n’, so we can write:
Water surface Area/n= 36, since we know that the water surface area of an aquarium is area of its base, we can rewrite the equation as
(l*b)/n= 36 i.e n= (l*b)/36……. Eqn 1,
assuming length as ‘l’ and breadth as ‘b’.So, if we can find the value of l and b or the product of l and b, we would get our required answer.
Statement-1St-I tells us about the edges of the aquarium being 60, 42 and 30, but it does not tell us about that the lengths of l, b and h (height of aquarium). Hence l, b can take any of the 2 values out of 60, 42 and 30. Hence the information provided is insufficient.
Statement-2St-2 tells us about the depth of water in the aquarium but provides no information about the length and breadths of the aquarium, hence st-2 also is insufficient
Combing Statement- 1 and Statement-2If we combine st- 1 & 2 we can interpret that height of the aquarium can’t be 30 as the depth of water is 40 cm > 30. So, 30 can be either l or b.
Assuming 30 to be as ‘b’ we can rewrite equation 1 as
n = (l *30)/36 = (l *5) /6….. Eqn 2We observe that ‘n’ has to be an integer as it is the no. of fishes, so ‘l’ can only take values which are multiple of 6. We know that ‘l’ can take values of either 60 or 42. In this case both are multiples of 6 and hence we will not have a unique answer.
However, had the edges of the aquarium been 58 and 42, we would have been sure to get the value of ‘l’ as 42 and then could have calculated the unique value of ‘n’ by combining st-1 & 2.Hence, the
answer would have changed to Option C Regards
Harsh
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