明天就要一戰GMAT了，剛剛做了一次模擬，真的很沮喪，只有610，比報名時候完全沒
準備的第一次模擬還要低...唉，不知道這一整個寒假的準備會不會有成果.而且更心酸
的是數學錯了好多...不知道是不是腦子壞掉，現在都沒什麼自信了...
煩請大家幫忙解釋下這幾題，實在不太會...謝謝
1.If n is a positive integer and the product of all the integers from 1 to n,
inclusive, in a multiple of 990, what is the least possible value of n?
a. 10
b. 11
c. 12
d. 13
e. 14
2.
7.51 8.22 7.86 8.36 8.09 7.83
8.30 8.01 7.73 8.25 7.96 8.53
A vending machine is designed to dispense 8 ounces of coffee into a cup. After
a test that recorded the number of ounces of coffee in each of 1000 cups dispensed
by the vending machine, the 12 listed amounts, in ounces, were selected from
the data. If the 1000 recorded amounts have a mean of 8.1 ounces and a std dev
of 0.3 ounce, how many of the 12 listed amounts are within 1.5 std dev of the mean?
a. 4
b. 6
c. 9
d. 10
e. 11
3. For a certain race, 3 teams were allowed to enter 3 members each. A team earned
6-n points whenever one of its members finished in nth place, where 1<=n<=5.
There were no ties, disqualifications, or withdrawals. If no team earned more than
6 points, what is the least possible score a team could have earned?
a. 0
b. 1
c. 2
d. 3
e. 4
1﹣3答案分別是
b.11
e.11
d.3
不是很理解，想請教下為什麼？
先謝謝：）