MISSOULA, MT—For the seventh week in a row, Bill Trusky cheated his son Shane out of the boy's $3 allowance, the 8-year-old's father said Monday. "Sorry, Shane, I said it was double or nothing if you could sneeze with your eyes open," Trusky said. "But I'll tell you what: If you can mow the lawn—front and back—in 20 minutes, I'll pay you triple." Household sources report that Shane might have completed the task had Trusky not hurled a croquet ball in the mower's path 10 feet before his son finished.