1. Good post? |
Hi,

por favor, el seņor solve these for me![V]

1. When a positive integer 'n' is divided by '7', the quotient is 'q' and the remainder is 4. when '2n' is divided by 7 the remainder is one and the quotient in terms of 'q' is:

a. q/2
b. (q/2)+1
c. 2q
d. 2q+1
e. 2q+2

Ans: 2q+1

2. Let a1,a2,a3,.........an....... be a sequence of +ve nos. where a1=1 and for n>=1, a(n+1)=an + 4. Which of the foll. represents the nth term of the sequence?

a.4n-3
b.4n-1
c.4n
d.4n+1
e.4n+4

Ans: 4n-3

2. Good post? |
Hi Synthia,

I'd suggest writing out the equations on a paper to solve these probs:

1) According to the first statement, n = (7*q)+4; (EQN 1)

According to the second statement, 2n = (7*x)+1; (EQN 2)
where x = new quotient

Double the first equation, equate the RHS of both equations and then solve for x.

x = 2q+1;

As for your second problem, its a case of an arithmetic series, where the nth term of a sequence is given by:-

an = a1+(n-1)*d; where d = common difference between consecutive nos.

here d = a(n+1) - a(n) = 4, according to data.

therefore, an = 1+(n-1)*4, since a1 here is 1. That is an = 4n-3;

3. Good post? |
Hi Xaero,

thanks a lot! Hey, now that I know it, it seems really very simple!! Thanks again pal!BTW, do we have to know all the series formulae before we take GRE?

4. Good post? |
Hi Synthia,

It sure helps to brush up all your high school math formulae, esp those that havent be used too often, such as AP, GP, HP and all those stuff..

5. Good post? |

## Re: Powerprep problems

Done, I mean I solve it myself
1) 2q+1
2) 4n-3

6. Good post? |

## Re: Powerprep problems

Another approach-
It always helps to just pick numbers to solve such questions. It saves a lot of time too.

1) Remainder of n/7 is 4.
Choose the nearest number which is n=11.
So, q = 1.

Now, 2n = 22, and 22/7 has q1=3 and remainder = 1.
Clearly the only true relation between q1 and q from the answer choices given is q1 = 2q+1

2) Given a1=1 => a2 = a1 +4 = 5.
Substitute n=2 in all given solutions,
'4n-3' is the only one that gives a 5.

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