Question 773495
Please check your question.
The question is: "At what average speed should he be driving so that he will reach Bedok at 13 00?"
You have already mentioned that "If he drives at an average speed of 90km/h,he will reach his destination at 13 00".
So the answer is 90 kmph!?
Something is wrong / missing in the question - pl check and re-post.