How Islam Began - In Ten Minutes

[sitifan]

Can I use "within 10 minutes" instead of "in 10 minutes" here?

 

[5jj]

No.

 

[sitifan]

Can I use "within 25 minutes" instead of "in under 25 minutes" here?

 

[5jj]

No.

 

[sitifan]

What's the difference in meaning between "in under 25 minutes" and "within 25 minutes"?

 

[probus]

I don't think there is much difference in meaning. The thing is, however, that the within construction is unnatural. A native speaker would use "in less than" rather than "within".