/AB/ = 3cm, /BC/= 7cm and /AC/ = 5cm, X and Y are points on the line /AB/ and /AC/ respectively. Calculate which of the points X and Y is closer to A and by how much?

Interpreting as: points

Assuming "points" is a unit

Assuming desktop publishing points for "points"
Input interpretation:
pt (desktop publishing point)

Conversions to other units:
1 pt | 10 dpt (desktop publishing decipoints)
| 1.004 Johnson points
| 0.9383 French Didot points
| 0.1667 desktop publishing lines
| 0.08333 picas
| 0.01389 inches
| 352.8 µm (micrometers)
| 0.3528 mm (millimeters)
| 0.03528 cm (centimeters)
| 3.528×10^-4 meters

2+1=3 that’s your answer