JEE MATHEMATICS MCQ: RELATIONS

1 Easy

1 of 1

Application +4 | -1

Suppose that

A_1, A_2, A_3 \ldots A_{30}

are thirty sets each containing 6 elements and

B_1, B_2, B_3 \ldots B_n

are

n

sets each containing 3 elements. If

\bigcup\limits_{{i=1}}^{30} A_i=S=\bigcup\limits_{{i=1}}^n B_i

and each element of

{S}

belongs to exactly

10 A_i S

and to exactly

9 B_i S

then

{n}=

View answer and explanation

Correct option: A

Option A (54) is correct because it is the number of sets

B_i

calculated based on the given conditions of union and element frequency.

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