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

Redeem

Pensils

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Junior | Next Rank: 30 Posts
Posts: 14
Joined: Tue Dec 29, 2009 11:03 pm

Pensils

by nlpfollower » Mon Mar 15, 2010 9:37 pm
Three types of pencils, J,K, and L, cost $0.05, $0.10, and $0.25 each, respectively. If a box of 32 of these pencils costs a total of $3.40 and if there are twice as many K pencils as L pencils in the box, how many J pencils are in the box?

(A) 6
(B) 12
(C) 14
(D) 18
(E) 20


OA is C.
Top
Source: — Problem Solving |
User avatar
Legendary Member
Posts: 1132
Joined: Mon Jul 20, 2009 3:38 am
Location: India
Thanked: 64 times
Followed by:6 members
GMAT Score:760

by harsh.champ » Mon Mar 15, 2010 10:22 pm
nlpfollower wrote:Three types of pencils, J,K, and L, cost $0.05, $0.10, and $0.25 each, respectively. If a box of 32 of these pencils costs a total of $3.40 and if there are twice as many K pencils as L pencils in the box, how many J pencils are in the box?

(A) 6
(B) 12
(C) 14
(D) 18
(E) 20


OA is C.
L = 2K
so, J+K+2K = 32
or 0.05*J + 0.10*K + 0.25*2K = 3.40
or 5J + 10K + 50K = 340
Putting J=32-3K
we have 5(32-3K) +60K = 340
160 + 45K = 340
45K=180
K=4
J = 32 - 4x3

Is the answer wrong??
My answer is cuming to be 20.
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
Top
Master | Next Rank: 500 Posts
Posts: 232
Joined: Sun Feb 28, 2010 10:47 pm
Thanked: 10 times

by Phirozz » Mon Mar 15, 2010 10:40 pm
nlpfollower wrote:Three types of pencils, J,K, and L, cost $0.05, $0.10, and $0.25 each, respectively. If a box of 32 of these pencils costs a total of $3.40 and if there are twice as many K pencils as L pencils in the box, how many J pencils are in the box?

(A) 6
(B) 12
(C) 14
(D) 18
(E) 20


OA is C.
J K L
0.05 0.10 0.25

For each L thr are two K
so 1L and 2K costs 0.45
Now u should solve from options
3 pencils(2K+1L) cost 0.45
18 pencils will cost 0.45*6 = 2.7
Rest 14 will cost 14*.05 = 0.7

2.7+0.7 = 3.4
so ans is C
Top
User avatar
Senior | Next Rank: 100 Posts
Posts: 51
Joined: Thu Mar 11, 2010 11:11 am
Thanked: 6 times

by lkm » Mon Mar 15, 2010 10:44 pm
Cost of the pencils:-

J = 0.05$
K = 0.10$
L = 0.25$

Total cost = 3.40$

Total pencils = J + K + L = 32 => equation (I)

and also K = 2L => equation (II)

Now using the cost factor, we can form the following equation:-

0.05J + 0.10K + 0.25L = 3.40

Simplifying the equation:-

=> 5J + 10K + 25L = 340 (multiplied by 100)
=> J + 2K + 5L = 68 (divided by 5) => equation (III)

Now using equation (I) and (III),

K + 4L = 36

Now using equation (II),

6L = 36

=> L = 6
=> K = 12
=> J = 32 - 18 = 14

Therefore answer is (C)
Top
Master | Next Rank: 500 Posts
Posts: 232
Joined: Sun Feb 28, 2010 10:47 pm
Thanked: 10 times

by Phirozz » Mon Mar 15, 2010 10:52 pm
harsh.champ wrote:
nlpfollower wrote:Three types of pencils, J,K, and L, cost $0.05, $0.10, and $0.25 each, respectively. If a box of 32 of these pencils costs a total of $3.40 and if there are twice as many K pencils as L pencils in the box, how many J pencils are in the box?

(A) 6
(B) 12
(C) 14
(D) 18
(E) 20


OA is C.
L = 2K
so, J+K+2K = 32
or 0.05*J + 0.10*K + 0.25*2K = 3.40
or 5J + 10K + 50K = 340
Putting J=32-3K
we have 5(32-3K) +60K = 340
160 + 45K = 340
45K=180
K=4
J = 32 - 4x3

Is the answer wrong??
My answer is cuming to be 20.
dude what u have done ???
let say x, y nd z are the number of pencils of each type of J, K and L respectively
its given, y = 2z also given x+y+z = 32
or x+3z = 32..................equation (1)
Now 0.05x+0.10y+0.25z = 3.40
we know y = 2z
so 0.05x+0.2z+0.25z = 3.40
or 0.05x+0.45z = 3.40..............equation (2)

Now solve the above two equations u ll get x = 14
Top
Post new topic Post Reply
• Page 1 of 1