Given:
Cost of mowers are $1017
[tex]\begin{gathered} \text{Cost paid in 7 months=7}\times54 \\ =378 \end{gathered}[/tex][tex]\begin{gathered} \text{Amount to be paid on 8th month=1017-378} \\ =\text{ \$639} \end{gathered}[/tex]Amount to be paid on 8th month is 639