Quant Problems

[sukh]

How many positive integers less than 30 are either a multiple
of 2, an odd multiple of 9, or the sum of a positive multiple of
2 and a positive multiple of 9 ?
(A) 27
(B) 26
(C) 25
(D) 24
(E) 23
Answer should be 26 instead of 25 ?


87, 77, 51, 65, 90, 33, 39, 74
Which of the following numbers is greater than three-fourths of
the numbers but less than than one-fourth of the numbers in the
list above?
(A) 35
(B) 40
(C) 52
(D) 58
(E) 80

[cans]

How many positive integers less than 30 are either a multiple
of 2, an odd multiple of 9, or the sum of a positive multiple of
2 and a positive multiple of 9 ?
(A) 27
(B) 26
(C) 25
(D) 24
(E) 23

<30. 14 even integers (2,...28)
9,27..
11,13,15,17,19,21,23,25,27,29.
that leaves 1,3,5,7
Thus 25. (total 29)

[cans]

87, 77, 51, 65, 90, 33, 39, 74
Which of the following numbers is greater than three-fourths of
the numbers but less than than one-fourth of the numbers in the
list above?
(A) 35
(B) 40
(C) 52
(D) 58
(E) 80

total = 8. order: ...77,87,90
IMO E

[cans]

Can you please post only one question per forum from next time.

[abhimanyu.tanwar]

87, 77, 51, 65, 90, 33, 39, 74
Which of the following numbers is greater than three-fourths of
the numbers but less than than one-fourth of the numbers in the
list above?
(A) 35
(B) 40
(C) 52
(D) 58
(E) 80

total = 8. order: ...77,87,90
IMO E

Hi Cans, could you please explain this one.

[shankar.ashwin]

Arranging in ascending order,

33,39,51,65,74,77,87,90.

Notice that 80 is the only number which is greater than 6 of the numbers and less than 2 of the given numbers.
Hence satisfies the condition

87, 77, 51, 65, 90, 33, 39, 74
Which of the following numbers is greater than three-fourths of
the numbers but less than than one-fourth of the numbers in the
list above?
(A) 35
(B) 40
(C) 52
(D) 58
(E) 80