Pahang is a large province within Malaysia. The edge of Pahang province is pretty much on the eastern outskirts of the connurbation of Kuala Lumpur.
To drive from Kuala Lumpur to the Pahang coast (the other side of Pahang province from the capital) can take as little as 4 hours, to give you an idea.
So basically, not that far. Depending on traffic, about an hour to get from roughly the city centre to the edge of Pahang. And 2-6 hours of driving to get to specific nice bits of Pahang.
To drive from Kuala Lumpur to the Pahang coast (the other side of Pahang province from the capital) can take as little as 4 hours, to give you an idea.
So basically, not that far. Depending on traffic, about an hour to get from roughly the city centre to the edge of Pahang. And 2-6 hours of driving to get to specific nice bits of Pahang.