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Q6:
A box
contains 10 light bulbs, fewer than half of which are defective. Two bulbs are to be drawn simultaneously from
the box. If n of the bulbs in box are
defective, what is the value of n?
(1) The probability that the two bulbs to be drawn will be defective
is 1/15.
(2) The probability that one of the bulbs to be drawn will be defective
and the other will not be defective is 7/15.
A.
Statement (1) ALONE is sufficient, but statement (2) alone is not
sufficient.
B.
Statement (2) ALONE is sufficient, but statement (1) alone is not
sufficient.
C. BOTH
statements TOGETHER are sufficient, but NEITHER statement ALONE
is sufficient.
D. EACH
statement ALONE is sufficient.
E.
Statements (1) and (2) TOGETHER are NOT sufficient.
Answer: C Is it bc for 2), x defective, 10-xnot defective, so the probability should be cx1*c10-x1
Q10:
Six
cards numbered from 1 to 6 are placed in an empty bowl. First one card is drawn and then put back
into the bowl; then a second card is drawn.
If the cards are drawn at random and if the sum of the numbers on the
cards is 8, what is the probability that one of the two cards drawn is numbered
5 ?
A.
1/6
B.
1/5
C.
1/3
D.
2/5
E.
2/3
Answer any clue?
The operation Θ is defined by x Θ y = 1/x + 1/y for all nonzero
numbers x and y. If z
is a number greater than 1, which of the following must be true?
I. x Θ (-z) = 0
II. z
Θ = 1
III.
Θ = z
A. I only
B. I and II
only
C. I and
III only
D. II and
III only
E. I, II,
and III
Answer:E Why 1) is right? we know nothing about the relation btwn x and z
Q37:
In a
meeting of 3 representatives from each of 6 different companies, each person
shook hands with every person not from his or her own company. If the representatives did not shake hands
with people from their own company, how many handshakes took place?
A.
45
B.
135
C.
144
D.
270
E.
288
Answer: B any clue
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