A man sold an article for Rs. 644 gaining
3
1
​
rd of his outlay. Find the cost price of the article.

Let the cost price (outlay) of the article be Rs. X.
Given:

Gain=
3
1
​
×X=
3
X
​

We know that:

Selling Price (SP)=Cost Price (CP)+Gain
644=X+
3
X
​

644=
3
4X
​

Solving for X:

4X=644×3
X=
4
644×3
​

X=161×3=Rs. 483