MathDB
2020 Individual #24

Source:

May 1, 2022
2020 Individual

Problem Statement

[asy] size(140); import geometry; dot((0,0));label("(0,0)(0,0)",(0,0),SW); dot((4,3)); dot((5,4));label("(5,4)(5,4)",(5,4),NE); draw((0,0)--(7,0), EndArrow); draw((0,0)--(0,6), EndArrow); add(grid(5,4)); [/asy] A leprechaun wishes to travel from the origin to a pot of gold located at the coordinate point (5,4)(5,4). If she can only move upwards and rightwards along the unit grid, must pass a checkpoint at (1,2)(1,2), and must avoid an evil thief at (4,3)(4,3), how many distinct paths can she take?
<spanclass=latexbold>(A)</span>7<spanclass=latexbold>(B)</span>15<spanclass=latexbold>(C)</span>21<spanclass=latexbold>(D)</span>45<spanclass=latexbold>(E)</span>126<span class='latex-bold'>(A) </span>7\qquad<span class='latex-bold'>(B) </span>15\qquad<span class='latex-bold'>(C) </span>21\qquad<span class='latex-bold'>(D) </span>45\qquad<span class='latex-bold'>(E) </span>126