Question
Quantitative Ability and Data Interpretation Question on LCM and HCF
The question given below consists of a question and two statements numbered I and II. You have to decide whether the data provided in the statements is sufficient to answer the question. Read both statements and answer accordingly.
What is the product of x and y?
Statement I. Both x and y are consecutive even multiples of 32.
Statement II. The LCM of x and y is 3584.
The data in both statements I and II together is necessary to answer the question.
The data either in Statement I alone or in Statement II alone is sufficient to answer the question.
The data in both statements I and II together is not sufficient to answer the question.
The data in Statement II alone is sufficient to answer the question, while the data in Statement I alone is not sufficient to answer the question.
The data in Statement I alone is sufficient to answer the question, while the data in Statement II alone is not sufficient to answer the question.
The data in both statements I and II together is necessary to answer the question.
Solution
Statement I: Both x and y are consecutive even multiples of 32.
So, if x=32(2k)=64k, then y=32(2k+2)=64(k+1)
Product of x and y=64k(64k+64)=4096k(k+1)
We do not know the value of ‘k’, so we cannot find the product.
Thus, Statement I alone is not sufficient to answer the question.
Statement II: The LCM of x and y is 3584.
Let x and y be ‘ha’ and ‘hb’, respectively, where ‘h’ is the HCF of x and y, and ‘a’ and ‘b’ are co-primes.
Thus, hab=3584
Product of x and y = ha(hb)=h2(ab)=3584h
We do not know the value of ‘h’, so we cannot find the product of x and y.
Using statements I and II together,
LCM of x and y = 64k(k+1)=3584
or, k(k+1)=56
or, k=7
Now, the product of x and y, i.e., 4096k(k+1) can be calculated.
Thus, both the statements are necessary to answer the question.
Hence, option A is the correct answer.