`G=(1−1/3).(1−1/6).(1−1/10).(1−1/15)`
`G=2/3⋅5/6⋅9/10⋅14/15`
`G=5/9⋅9/10⋅14/15 G=5/10⋅14/15`
`G=1/2⋅14/15`
`G=7/15`
...
`H=(1−1/21).(1−1/28).(1−1/36).(1−1/45)`
`H=20/21⋅27/28⋅35/36⋅44/45`
`H=45/49⋅35/36⋅44/45`
`H=25/28⋅44/45`
`H=55/63`
`=>` `G.H=7/15. 55/63= 11/27`
`G.H=11/27`