If Worker X was to cut the grass at a field alone, he would complete cutting the field in 19 minutes. <br> If Worker Y was to cut the grass by himself, he would take 12 minutes. <br> If Worker Z was to cut the grass by himself, he would also take 12 minutes. <hr> How long did the three of them take to cut the grass together? <br> Express your answer in mixed fraction. <br> <br> A$$\frac{B}{C}$$ <hr> A: <input min="0" type="number" class="lineinput" placeholder="?" /> B:<input min="0" type="number" class="lineinput" placeholder="?" /> C: <input min="0" type="number" class="lineinput" placeholder="?" />