To run a half marathon in 1:40, hold 7'38" per mile, i.e. 7.87 mph (4'44"/km). At that pace: 5K in 23'42", 10K in 47'24", half marathon in 1h40'00", marathon in 3h20'00".
Half marathon in 1:40: 7'38"/mile
1 track lap = 1'53"8
1 track lap = 1'53"8
To run a half marathon in 1:40, hold 7'38" per mile, i.e. 7.87 mph (4'44"/km). At that pace: 5K in 23'42", 10K in 47'24", half marathon in 1h40'00", marathon in 3h20'00".