Aptitude - Decimal Fraction - Discussion

Discussion Forum : Decimal Fraction - General Questions (Q.No. 14)
14.
The price of commodity X increases by 40 paise every year, while the price of commodity Y increases by 15 paise every year. If in 2001, the price of commodity X was Rs. 4.20 and that of Y was Rs. 6.30, in which year commodity X will cost 40 paise more than the commodity Y ?
2010
2011
2012
2013
Answer: Option
Explanation:

Suppose commodity X will cost 40 paise more than Y after z years.

Then, (4.20 + 0.40z) - (6.30 + 0.15z) = 0.40

0.25z = 0.40 + 2.10

z = 2.50 = 250 = 10.
0.25 25

X will cost 40 paise more than Y 10 years after 2001 i.e., 2011.

Discussion:
18 comments Page 1 of 2.

Bittu Rana said:   3 days ago
Very clear explanation. Thanks all.

Shailu said:   5 years ago
@Monisa.

Thank you for the clear explanation.
(2)

Gurleen said:   5 years ago
420 + 40x = 630 + 15x + 40.
420 + 40x = 670 + 15x,
25x=250,
x = 10years.
2001 + 10 = 2011.
(12)

Jyothi said:   7 years ago
Very clear answer, Thanks all.

Monisa said:   8 years ago
40 paise converted to rupees as 0.40 . each year x increase 0.4 and each year Y increase 0.15 so,
Year ---------------> X ----- Y
2001 ------------ 4.2 ----- 6.3
2002 ------------4.6 ----- 6.45
2003 ------------5 ----- 6.6
2004 ------------5.4 ----- 6.75
2005 ------------5.8 ----- 6.9
2006 ------------6.2 ----- 7.05
2007 ------------6.6 ----- 7.2
2008 ------------7 ----- 7.35
2009 ------------7.4 -----7.5
2010 ------------ 7.8 -----7.65
2011 ------------8.2 ----- 7.8

Convert it into rupees
X Y
820 780
their difference (820-780)=40.
therefore ans is 2011.
(20)

Om singh said:   8 years ago
4.20+.40z=6.30+.15z+.40,
.25z=2.10+.40,
Z=10.
(1)

Minar said:   8 years ago
4.20 + (.4*10) = 8.2.
6.30 + (.15*10) = 7.8.

How could it be 10 yrs?

Animesh said:   8 years ago
I solved by using arithmetic progression.

4.20+(n-1)0.40 = 6.30+(n-1)0.15 + 0.40.

And the answer which came is 11 i.e 2012.
(1)

Sankara Gomathi said:   9 years ago
Very clear this answer.

Thank you.

Himanshi sethi said:   10 years ago
@Moses.

They just convert paise into rupees.


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