first 2 places are odd [ 1,3,5,7,9] total ways = 5*5 = 25
last 2 places are even [ 0,2,4,6,8] total ways = 5*5 = 25

but 0 can't be more than once, hence last 2 digit 00 is avoided then total ways of last 2 places = 25 - 1= 24

total ways = 25*24 = 600

there is a phase shift of 5 for each number between first 5 and last 5.

take example of 1,2,3,4,5
6,7,8,9,10


hence sum of first 5 = sum of last 5 - 5*5 = 350

tough is the only word that comes to mind

Are the read GMAT passages of this much difficulty?

My answers:

1 - C
2 - D
3 - C
4 - B
5 - B
6 - E
7 - B
8 - A

A- criticize the motives of those who use risky financial strategies - author doesn't target anyone here B- challenge a common perception of financiers - not true C- describe the evolution and application of a certain financial device - the financial device is leveraged buyout - evolution is describ...

Posted: Tue Apr 27, 2010 8:22 am For millennia, the Nile River flooded nearly every year as a natural consequence of heavy summer rains on the Ethiopian Plateau; in the last century, as the population in the region exploded, the cycle of flooding interspersed with periodic drought caused widespread ...

First i got confused by the options A and C, but reading the opening sentence of the para again cleared the thought. The reason for quoting the person and saying still there are no great medicine experts highlights the scientific ignorance part. Option C is right but it misses on the fact that why h...