DS - Coats Q.

From stem SP of 20 = CP of 20


From 1 say cp = x sp = 2x p can be found Hence sufficient

From 2 also we have a relationship in terms of x Hence sufficient

Hence D

It can't be "D". Here's why:

First let deduce an equation from the word problem:
X = selling price
Y = purchase price
Z = Profit

Therefore: 20X – 20Y = Z --- Let's call it Equation 1

Are goal here is to find Z. Now let's look at statements 1 and 2 individually.

1.

20(2X) – 20Y = 2400
40X – 20Y = 2400
2X – Y = 2400 --- Let's call it Equation 2

We can’t solve this further because we have 3 variables in Equation 1 and we need 3 distinct equations to solve this further.

Now lets look at statement 2

2. From the statement we can deduce the following equation:
20(X+2) – 20Y = 440
20X + 40 – 20Y = 440
X + 2 – Y = 22
X – Y = 20 --- Let's call it Equation 3

We are faced with a similar situation as we had encountered in statement 1. But wait, we don't need another distinct equation. If we multiply Equation 3 by “20” we get:

20X – 20Y = 400

AH! We only need statement 2 to answer this question. Therefore, the answer is “B”.

Thanks for the correction ..it shd be B