A sum of Rs. 1,48,000 was distributed among four employees—Arun, Bipin, Chetan and Dheeraj—such that Bipin gets 20 % more than Arun and Chetan gets an amount equal to 50 % of the sum of what Arun and Bipin get together. If Dheeraj gets Rs. 40,618, what is the difference in the amounts received by Bipin and Chetan?