Question: How do I solve this question using simultaneous equations?

I know this is cheeky but i was wondering if there was anyone out there that would be willing to pretty much do this question for me? i have been at this all night and still not the slightest clue. Any help would be much apprefiated. 

1. 1.    Below are 4 questions that require solving problems by formulating simultaneous equations. Solve each question and explain the method you used. What other methods could be used other than those you have used to solve here. (total 30 marks)

(a)  A penalty clause states that a groundwork’s sub-contractor will forfeit a certain sum of money for each day that they are late in completing a contract (i.e. the sub-contractor gets paid the value of the original contract less any forfeit). If they are 6 days late they receive £5000 if they are 14 days late they receive £3000. (8marks)

1. a.    Find the amount of the daily forfeit
2. b.    Determine the value of the original contract.

(b)  The total cost of purchasing 2 excavators, A and B is £30,000. The 2 tonne excavator costs £2,000 more than the 1.5 tonne excavator. Find the individual cost for each excavator. (7marks)

(c)  You are estimating costs for a heat recovery installation. You know that 100m of 100mm dia ducting and 8 bends cost £100 and 150m of 100mm ducting and 10 bends cost £147.50. Find the cost for 1m of ducting and 1 bend. (8marks)

(d)  You are a Site Manager who is organising a lift utilising a tower crane you have on site. You know that the Force (F) in Newtons required to lift a load (W) in Newtons is represented by the equation F = aW + b. You know that a force of 100N lifts a load of 180N and a force of 150N lifts a load of 280N. Find the values of a and b and the force required to lift a load of 500N. (7marks)