GMATPrep questions - need a better approach for these

for the 1st question..i wrote the lowest prime 6 times

2 x 2 x 2 x 2 x 2 x 2 = =64

then changed one 2 to a 3

2 x 2 x 2 x 2 x 2 x 3 = = 96

so two different ways

64 and 96 are two digits..

let's just say they were looking for 6 primes with 2 or 3 digits and must be under 150...

then there would be 3

2 x 2 x 2 x 2 x 3 x 3 = 148

sorry..explanation isn't the best..just figured get the product as small as possible which mean all the primes would have to be 2




2nd question..don't really have a fast way per se....i mean..it's fast for me..but I don't use a formula

first i quickly ranked the days

mon. + tue. + wed + thurs + sun + fri + sat

1st five days in no particular order

1. if thurs = 8
wed = 7
tue = 6
mon = 5
sun = 10
used consecutive integers and sun as 10 so that i can try to minimize the value for thursday (or equate it to 11)

sum for 5 days is 36 so fri + sat = 44

friday could be 11 or 12 because 11 + 23 = 44 or 12 + 22= 44 and using 11 or 12 would satisfy fri < sat

so 1 is insufficient


2. sat = 38
other 6 days must sum to 52...i assume fri = 11
the other days must be < 11
fri = 11
sun = 10
thurs = 9
wed = 8
tue = 7
mon = 6
sat = 38
total = 89

since the total must = 90 friday can't be 11..friday must be greater than 11



it's not the best explanation...but that's the way it's easier for me to understand...the explanation took a lot longer than the actual time to work it out.....it took me about 1 1/2 minutes

Hi lagomez
Thanks for taking the efforts to explain your approach...
I think i get the idea

thank you so much.