He was riding the motorcycle at a speed of between 100 and 110 k.m per hour.

[thehammer]

Are the following sentences correct?

1- He was riding the motorcycle at a speed of between 100 and 110 k.m per hour.

2- He was riding the motorcycle at a speed of from 100 to 110 k.m per hour.

 

[Skrej]

Neither is grammatical, but they're understandable.

A few possible variations:
He was riding the motorcycle at speeds of 100 to 110 km per hour.
He was riding the motorcycle between 100-110 km per hour.
He was speeding on the motorcycle up to 110 km per hour.
He was driving the motorcycle upwards of 110 km per hour.

 

[thehammer]

Thank you.

Can I say 'at a speed of somewhere between 100 and 110..'?

 

[Tarheel]

It's OK.

 

[SoothingDave]

There is no period in "km" or any other metric unit of measure. Or any American units, either.

 

[Rover_KE]

... and it's wrong to put two dots after '110' (post '3).