GMAT Problem Solving Discussions

MBA
743

@carobee,
is the answer Ci.e. 2 integers.

my explanation is...let us take 5 consec integers as-- (n-2)+(n-1)+n+(n+1)+(n+2)=35,; where n comes out to be 7...

substituting it to get various integers we have....5,6,7,8,9...so only 5&7 are prime...

am i right???

regards
Jakhar


The sum of 5 consecutive integers is 35. How many of the five consecutive integers are prime numbers?
a) 0
b) 1
c) 2
d) 3
e) 4





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744

i even tried the question with the following set of integers...

n,n+1,n+2,n+3,n+4...

i got the same answer again...

regrds

Jakhar

745

jakhar
lets wait for other to drill their minds...

746

@carobee,
sorry for jumping the gun,,

willl wait ..

regards

Jakhar

jakhar
lets wait for other to drill their minds...
747
The sum of 5 consecutive integers is 35. How many of the five consecutive integers are prime numbers?
a) 0
b) 1
c) 2
d) 3
e) 4





******************************************************
If my post benefits you then don't forget to thank me

let the 5 nos. be x,x+1,x+2,x+3,x+4,x+5...solving for equation, u get x = 5
hence, nos. are 5,6,7,8,9 out of which 5 and 7 are prime nos.

hence, answer is C...
748
The sum of 5 consecutive integers is 35. How many of the five consecutive integers are prime numbers?
a) 0
b) 1
c) 2
d) 3
e) 4





******************************************************
If my post benefits you then don't forget to thank me

The sum of 5 consecutive integers is 35

=> The numbers should lie on either side of average ie. 35/5=7

5 and 7 are the only primes among 5,6,7,8,9

Ans : C
749

How many intergers n are there such that
1
A)Five
B)Four
C)Three
D)Two
E)Zero

Could u plz clarify about that prob

750
The sum of 5 consecutive integers is 35

=> The numbers should lie on either side of average ie. 35/5=7

5 and 7 are the only primes among 5,6,7,8,9

Ans : C


i think that would be the best way to solve the above prob.
751
How many intergers n are there such that
1
A)Five
B)Four
C)Three
D)Two
E)Zero

Could u plz clarify about that prob

For 1
n cannot have any -ve value as it will lead to 5n+5 n cannot have any value greater than or equal to 4, coz that will lead to 5n+n >25

n can have only 4 integer values = 0,1,2,3

Ans : B
752

HI,
my take.... B.(there are 4 integers that satisfy the given condition.
take n=0 , 5n+5 comes out to be 5, 1take n=1 , 5n+5 comes out to be 10, 1similarly for n=2 and n=3 the condition would be satisfied

i hope it helps

Regards

Jakhar





ow many intergers n are there such that
1
A)Five
B)Four
C)Three
D)Two
E)Zero

Could u plz clarify about that prob

753
The sum of 5 consecutive integers is 35. How many of the five consecutive integers are prime numbers?
a) 0
b) 1
c) 2
d) 3
e) 4



******************************************************
If my post benefits you then don't forget to thank me


Ans : C)

The "middle number" should be near 7 because 35/5 = 7. Since 5 + 6 + 7 + 8 + 9 = 35, 5 and 7 are prime numbers
754

How many different positive integers exist between 10^6 and 10^7, the sum of whose digits is equal to 2?

  1. 6
  2. 7
  3. 5
  4. 8
  5. 18
755
How many different positive integers exist between 106 and 107, the sum of whose digits is equal to 2?


  1. 6
  2. 7
  3. 5
  4. 8
  5. 18

Can you pls check the question.

How many different positive integers exist between 106 and 107

??? between 106 and 107 ???
756
Can you pls check the question.

How many different positive integers exist between 106 and 107

??? between 106 and 107 ???

i have done the corrections please check now
757
How many different positive integers exist between 10^6 and 10^7, the sum of whose digits is equal to 2?

  1. 6
  2. 7
  3. 5
  4. 8
  5. 18

7 integers :

1000001
1000010
1000100
1001000
1010000
1100000
2000000


Ans : B
758

A certain car averages 25 miles per gallon of gasoline when driven in the city
and 40 miles per gallon when driven on the highway. According to these rates,
which of the following is closest to the number of miles per gallon that the car
averages when it is driven 10 miles in the city and then 50 miles on the
highway?

28 30 33 36 38

759
A certain car averages 25 miles per gallon of gasoline when driven in the city
and 40 miles per gallon when driven on the highway. According to these rates,
which of the following is closest to the number of miles per gallon that the car
averages when it is driven 10 miles in the city and then 50 miles on the
highway?

28 30 33 36 38

36

Ans. D

Let me know if this is correct...i'll post the complete soln.
760

D is correct.
However please tell me what is the flaw in my approach:

25 (1/6) + 40 (5/6)
( 1/6th of the time driven in the city and 5/6th of the time driven on highway)
I am getting 37.5.

761
D is correct.
However please tell me what is the flaw in my approach:

25 (1/6) + 40 (5/6)
( 1/6th of the time driven in the city and 5/6th of the time driven on highway)
I am getting 37.5.


You should look at the fuel consumed when driving in the city and then the fuel used up in the highway and then calculate based on that ..

in this .4 gallon for the city..1.25 gallon for the highway..

u get 60 kilometers in 1.65 gallons..
762
How many different positive integers exist between 10^6 and 10^7, the sum of whose digits is equal to 2?

  1. 6
  2. 7
  3. 5
  4. 8
  5. 18

Find the number of such integers existing for a lower power of 10 and extrapolate the result of the present case.

Between 10 and 100, that is 101 and 102, we have 2 numbers, 11 and 20.
Similarly, between 100 and 1000, that is 102 and 103, we have 3 numbers, 101, 110 and 200.

Therefore, between 106 and 107, one will have 7 integers whose sum will be equal to 2.