make all the denominators same ( make them 9!) and then compare the fractions.bhumika.k.shah wrote:Which of the following fractions has the greatest value?
A.3 / 8!
B.6*(4!) / 5*(9!)
C.4*(3!) / 9!
D.3 / 5*(7!)
E.14 / 5*(8!)
Quicker and new approaches required.
Source : MGMAT QBANK
IS it B?bhumika.k.shah wrote:Which of the following fractions has the greatest value?
A.3 / 8!
B.6*(4!) / 5*(9!)
C.4*(3!) / 9!
D.3 / 5*(7!)
E.14 / 5*(8!)
Quicker and new approaches required.
Source : MGMAT QBANK
I tried this whole problme in my mind.. It was confusing ....!!bhumika.k.shah wrote:[spoiler]OA D
Each fraction's denominator contains a factorial. Since any smaller factorial divides any larger factorial, any of the factorials smaller than 9! can be multiplied by appropriate terms. (For instance, multiplying 7! by yields 9!.) Therefore, the common denominator of all the fractions is 5(9!).
In (A) the numerator and denominator must be multiplied by 5 × 9; in (C), by 5; in (D), by 8 × 9; and in (E), by 9. No multiplication is necessary in (B).
The fractions now look like this:
(A)
3 × 9 × 5 / 5(9!)
=135 / 5(9!)
(B)
6 × 4 × 3 × 2 × 1/ 5(9!)
= 144 / 5(9!)
(C)
4 × 3 × 2 × 1 × 5/ 5(9!)
= 120/ 5(9!)
(D) 3 × 8 × 9/ 5(9!)
= 216 /5(9!)
(E) 14 × 9 / 5(9!)
= 126 / 5(9!)
Now that the denominators are all the same, we can directly compare the numerators. 216 is the largest numerator.
The correct answer is D.[/spoiler]
so, we have to compareharshavardhanc wrote:make all the denominators same ( make them 9!) and then compare the fractions.bhumika.k.shah wrote:Which of the following fractions has the greatest value?
A.3 / 8!
B.6*(4!) / 5*(9!)
C.4*(3!) / 9!
D.3 / 5*(7!)
E.14 / 5*(8!)
Quicker and new approaches required.
Source : MGMAT QBANK
certainly not !gmatmachoman wrote:@Harsha Bhai,
Can u try this prblm without using pen/Paper.. & that too in 1 min??
we'll do the circus later, for now the problem is fixed in no more than the ideal 2 minutesgmatmachoman wrote:@Harsha Bhai,
Can u try this prblm without using pen/Paper.. & that too in 1 min??
Same here, I have in point of fact divided my brain in two parts, LEFT and RIGHT. In the LEFT part, there's nothing RIGHT, and in the RIGHT part, there's nothing LEFTharshavardhanc wrote:certainly not !gmatmachoman wrote:@Harsha Bhai,
Can u try this prblm without using pen/Paper.. & that too in 1 min??
Buddy, to tell you I only think on paper because whenever i have tried to solve questions in my mind, I've always got an incorrect answer. I'm really a "slow head"
ROFLsanju09 wrote:
Same here, I have in point of fact divided my brain in two parts, LEFT and RIGHT. In the LEFT part, there's nothing RIGHT, and in the RIGHT part, there's nothing LEFT
harshavardhanc wrote:sanju09 wrote:congrats Govind, we're 3 nowharshavardhanc wrote:ROFLgmatmachoman wrote:@Harsha Bhai,
Can u try this prblm
Same here, I have in point of fact divided my brain in two parts, LEFT and RIGHT. In the LEFT part, there's nothing RIGHT, and in the RIGHT part, there's nothing LEFT
but, we've caught you typing some great sense here, rock ukstv wrote:A.3 / 8! B.6*(4!) / 5*(9!) C.4*(3!) / 9! D.3 / 5*(7!) E.14 / 5*(8!)
Since the job is to find the max value compairing will yield thhe result with minimum calculation.
A and E both have 8! in the denominator (D) multiply by 5 the numerator (N) of A will be 15 , N of B = 14
B and C both have 9! in the denominator (D) multiply by 5 the N of B = 6! and C 5!
A 15/8! and B 6!/9! D 15/7! obvious that D is > A as (N) is the same
between B and D - am still doing it mentally.
