BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

Cube-->Cuboid

Expert replies
by harsh.champ » Sun Feb 07, 2010 12:01 pm
78 identical cubes each with 2 cm edge are joined together to form a cuboid. If the perimeter of the base of the cuboid is 64 cm, then the number of cubes along the height of the cuboid is

(A)3
(B)6
(C)2
(D)4
(E)Cannot be determined

The correct answer is C.
It takes time and effort to explain, so if my comment helped you please press Thanks button :)



Just because something is hard doesn't mean you shouldn't try,it means you should just try harder.

"Keep Walking" - Johnny Walker :P
Join the discussion
Source: — Problem Solving |

by shashank.ism » Sun Feb 07, 2010 12:06 pm
harsh.champ wrote:78 identical cubes each with 2 cm edge are joined together to form a cuboid. If the perimeter of the base of the cuboid is 64 cm, then the number of cubes along the height of the cuboid is

(A)3
(B)6
(C)2
(D)4
(E)Cannot be determined

The correct answer is C.

Let A & B be the no. of cubes on side of cuboid and C be the no. on height of cuboid
so total no = A*B*C = 78
Also perimeter = 64
--> 2 (2A+2B) = 64
--> A+B =16
Now 78 = 13* 3*2 on factorization
and 13+3 =16 so C=2

Hence,The correct answer is C.[/quote]
Last edited by shashank.ism on Sun Feb 07, 2010 2:01 pm, edited 1 time in total.
My Websites:
www.mba.webmaggu.com - India's social Network for MBA Aspirants

www.deal.webmaggu.com -India's online discount, coupon, free stuff informer.

www.dictionary.webmaggu.com - A compact free online dictionary with images.

Nothing is Impossible, even Impossible says I'm possible.
Join the discussion

by ajith » Sun Feb 07, 2010 12:40 pm
harsh.champ wrote:78 identical cubes each with 2 cm edge are joined together to form a cuboid. If the perimeter of the base of the cuboid is 64 cm, then the number of cubes along the height of the cuboid is

(A)3
(B)6
(C)2
(D)4
(E)Cannot be determined

The correct answer is C.

say a,b,c are the num of the cubes on the each of the side of the cuboid

abc =78
a+b = 16

abc = 13*2*3

since a,b,c all are integers

a =13, b =3 and c =2 is one solution
a =3, b =13 and c =2 us another
c=2 in any case
Always borrow money from a pessimist, he doesn't expect to be paid back.
Join the discussion

by onedayi'll » Sun Feb 07, 2010 12:56 pm
shashank.ism wrote:
harsh.champ wrote:78 identical cubes each with 2 cm edge are joined together to form a cuboid. If the perimeter of the base of the cuboid is 64 cm, then the number of cubes along the height of the cuboid is

(A)3
(B)6
(C)2
(D)4
(E)Cannot be determined

The correct answer is C.
The correct answer is C.
[/quote]


shashank.ism,

You're not providing any explanation just writing the correct answer....
That's looks like you're doing copy and paste.

I think its not the proper way.
Join the discussion

by onedayi'll » Sun Feb 07, 2010 1:03 pm
ajith wrote:
harsh.champ wrote:78 identical cubes each with 2 cm edge are joined together to form a cuboid. If the perimeter of the base of the cuboid is 64 cm, then the number of cubes along the height of the cuboid is

(A)3
(B)6
(C)2
(D)4
(E)Cannot be determined

The correct answer is C.

say a,b,c are the num of the cubes on the each of the side of the cuboid

abc =78
a+b = 16

abc = 13*2*3

since a,b,c all are integers

a =13, b =3 and c =2 is one solution
a =3, b =13 and c =2 us another
c=2 in any case



Hi,

How did u got a+b = 16?
Join the discussion

by ajith » Sun Feb 07, 2010 1:05 pm
onedayi'll wrote:
ajith wrote:
harsh.champ wrote:78 identical cubes each with 2 cm edge are joined together to form a cuboid. If the perimeter of the base of the cuboid is 64 cm, then the number of cubes along the height of the cuboid is

(A)3
(B)6
(C)2
(D)4
(E)Cannot be determined

The correct answer is C.

say a,b,c are the num of the cubes on the each of the side of the cuboid

abc =78
a+b = 16

abc = 13*2*3

since a,b,c all are integers

a =13, b =3 and c =2 is one solution
a =3, b =13 and c =2 us another
c=2 in any case



Hi,

How did u got a+b = 16?
Perimeter =64 cm and each cube has 2cm breadth

so 2*a*2cm+2*b*2cm =64
4(a+b) =64
a+b = 16
Always borrow money from a pessimist, he doesn't expect to be paid back.
Join the discussion