English: Panel (a) is an undifferentiated graph representing consumers' preferences for goods X and Y. The three parallel lines of Rs.300, Rs 400. And Rs.500 are called budget lines. And the slope of these three lines is the same, which implies that the prices of the two goods are constant, while the budget line farther from the origin indicates a larger budget amount. The three points R, S, and T in the graph hint different preference combinations. The line connecting these three points is called the income consumption curve (ICC). By extending Panel (a) to Panel (b), the Engel curve for good X is obtained by connecting the points R’, S’, and T’.