First of all, thank your for kind reply, please note that i have calculate the 5000 based on the following calculation :
37500 + (4000 * 100/80) = 42,500.
Yes, i have extended by 5000, so based on your reply, if the question stated its GROSS, no need for the above calculation, we take the figure which is given in the question and extend the limits, however if its not stated as GROSS we then have to multiple it with 100/80 to obtain the new limit.