A minibus had 23 passengers at the beginning of a journey. twelve passengers alighted at the first stop while 9 boarded six of those who boatded at the first stop alighted at the second stop and 12 got in .the minibus should not stop again up to the final destination .the charges from the starting point were $50 up to the first stop ,$70 up to the second stop and $85 up to the final destination. how many passengers alighted at the final destination. how many passengers were ferried by the minibus through the journey. how much money was collected during the trip. maths question