The price of 10 chairs is equal to that of 4 tables. The price of 15 chairs and 2 tables together is Rs. 4000. The total price of 12 chairs and 3 tables is:
[A].
Rs. 3500
[B].
Rs. 3750
[C].
Rs. 3840
[D].
Rs. 3900
Answer: Option E
Explanation:
Let the cost of a chair and that of a table be Rs. x and Rs. y respectively.
Then, 10x = 4y or y =
5
x.
2
15x + 2y = 4000
15x + 2 x
5
x = 4000
2
20x = 4000
x = 200.
So, y =
5
x 200
= 500.
2
Hence, the cost of 12 chairs and 3 tables = 12x + 3y
Easy way: If 10C=4T then 5C=2T......(1)
given 15C+2T=4000
using (1) we get C=200 & T=500
Hence we can find remaining...
Dilip said:
(Fri, Jan 28, 2011 11:15:47 AM)
15C+2T=4000
30C+4T=8000
10C=4T
30C+10C=8000
40C=8000
C=200
15(200)+2T=4000
3000+2T=4000
2T=1000
T=500
12(200)+3(500)=3900
Premchand said:
(Sat, Apr 2, 2011 03:17:08 PM)
10c=4t then 1t=2.5c
15c+2t=4000 that is chair calculation 20c=4000 one chair is 200 12x200=2400 3t=7.5c that is 1500 total counting is 3900
Martin said:
(Thu, Jun 30, 2011 08:13:55 AM)
10c=4t
15c+2t=4000
take the cost of c & t is 2000 b'coz 10c + 4t cost is same. and divid 2000 by 10 as well as 4 and get c & t cost as,
1t-500
1c-200
therefore,
12c-2400 + 3t-1500 = 3900.
Lorna said:
(Sat, Sep 17, 2011 11:37:38 PM)
How did they get the 20 that was used 20 divide 4000 ?
Manojit said:
(Tue, Feb 7, 2012 07:15:09 PM)
@Lorna
15x+2*5x/2=4000 [2is multiply of 5x/2]
15x+5x=4000
20x=4000
x=4000/20
x=200
15x + 2y = 4000
15x + 2 x
