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#1 Re: Help Me ! » Floor functions » 2015-03-31 11:49:13

Why did you guys remove {x}

How do u solve this?

#2 Re: Help Me ! » Log propeties » 2015-03-31 11:45:28

Oh I get it, I'll post when I am not on mobile

#3 Help Me ! » Log propeties » 2015-03-30 08:48:17

cooljackiec
Replies: 2

11. Write as the sum or difference of logarithms:

#6 Help Me ! » Floor functions » 2015-03-25 15:45:22

cooljackiec
Replies: 14


{a} denotes the fractional part of a

#7 Re: Help Me ! » Sequence » 2015-03-25 09:25:45

I got (a+2e-3)^2=(a+3e+2)(a+e-4) which gives 10a+e^2+22e-4=0

#8 Re: Help Me ! » Telescoping sum? » 2015-03-25 09:19:50

Derp I thought that 3^0+1 was 1 my bad

#9 Re: Help Me ! » Telescoping sum? » 2015-03-25 09:17:34

I tried S=the thing posted and S/3, not exactly sure how to do it, I have 3^k/(3^k+1)

#10 Re: Help Me ! » Sequence » 2015-03-25 09:14:57

bob bundy wrote:

with r = common ratio.

So eliminate b, c and d from the GP equations and then divide the first by the second and first by the third to eliminate r and leave a pair containing just a and e.

How exactly do you "eliminate b"

#11 Re: Help Me ! » Telescoping sum? » 2015-03-25 09:08:38

Using the above, how would you get 2?

#12 Re: Help Me ! » Telescoping sum? » 2015-03-24 16:38:59

Sounds intuitive, can you try to explain what your thought process was?

#13 Re: Help Me ! » Telescoping sum? » 2015-03-24 14:32:24

o.O how in the world do you get that...

#14 Re: Help Me ! » Sequence » 2015-03-24 08:30:56

I used the method before I posted but didn't get anywhere hmm

#15 Help Me ! » Sequence » 2015-03-24 05:18:48

cooljackiec
Replies: 14

Find the arithmetic sequence a, b, c, d if a−2, b−4, c−3, d+2 is a geometric sequence.

#19 Help Me ! » frobenius problem » 2014-07-14 05:15:30

cooljackiec
Replies: 2

A country has three denominations of coins, worth 7, 10, and 53 units of value. What is the maximum number of units of currency which one cannot have if they are only carrying these three kinds of coins?

I know the formula for 2 denominations, but I don't know how to do one with 3.

#20 Re: Help Me ! » bases » 2014-06-27 04:44:37

is the number of integers, less than or equal to n, that are relatively prime to n.
is the number of divisors of n

#21 Re: Help Me ! » bases » 2014-06-26 04:25:47

Thanks, this doesn't exactly relate to bases, but:

Find all positive integers n such that

.

#22 Re: Help Me ! » bases » 2014-06-25 08:20:08

The harmonic mean of two positive numbers is the reciprocal of the arithmetic mean of their reciprocals. For how many ordered pairs of positive integers (x, y) with x < y is the harmonic mean equal to 6^{20}?

#23 Re: Help Me ! » bases » 2014-06-21 10:13:51

Ok, so that 0.251 thing was correct. and the answer is 30 for the sum of the squares of the digit thing.

#24 Re: Help Me ! » bases » 2014-06-20 15:25:28

Given a rational number, write it as a fraction in lowest terms and calculate the product of the resulting numerator and denominator. For how many rational numbers between 0 and 1 will 20! be the resulting product?

We have fraction m/n. I wrote the prime factorization of 20!, but I can't seem to find the largest possible value of m. Once I get the largest value of m, then I can just count the number of divisiors of m, but what do I do to get m.

Also:
Find the sum of all positive rational numbers that are less than 10 and that have denominator 30 when written in lowest terms.

#25 Re: Help Me ! » bases » 2014-06-20 15:20:57

Hmm 32/127 is what i found too

Also, anonimistefy, I got the 1st question. It was 30, not 32.

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