A man misses a train by 1 hour if he travels at a speed of 4 kmph. If he had increased his speed to 5 kmph, he would gave still missed the train by 24 minutes. At what speed should he have travelled so that he reached the station exactly on time?
In the following question, out of the four alternatives, select the alternative which will improve the bracketed part of the sentence. In case no improvement is needed, select "no improvement".
I (has failed) in my eleventh grade chemistry paper.