Answer :
Time period=7.1s
[tex]\boxed{\sf Frequency=\dfrac{1}{Time\:Period}}[/tex]
[tex]\\ \tt\longmapsto Frequency=\dfrac{1}{7.1}[/tex]
[tex]\\ \tt\longmapsto Frequency=0.14Hz[/tex]
Time period=7.1s
[tex]\boxed{\sf Frequency=\dfrac{1}{Time\:Period}}[/tex]
[tex]\\ \tt\longmapsto Frequency=\dfrac{1}{7.1}[/tex]
[tex]\\ \tt\longmapsto Frequency=0.14Hz[/tex]