# Reciprocal sum is exactly 1 now

Number Theory Level 4

Find the number of solutions to the equation $\frac{1}{a}+ \frac{1}{b}+ \frac{1}{c} +\frac{1}{d}=1$ where $$a,\ b,\ c,\ d$$ are positive integers and $$a\leq b \leq c \leq d.$$

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