Question 1090673
Let n be the number of friends with wallets. Then, the total number of diners would be n+3. So:
1120/(n+3) +84=1120/n
1120n+84(nē+3n)=1120(n+3)
84nē+252n-3360=0
nē+3n-40=0
(n+8)(n-5)=0
n=5 or -8
n=5
n+3=8
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