1. Write down a formula for each situation: a) A plumber has a fixed call- out charge of \\( \\$ 80 \\) and has an hourly rate of \\( \\$ 60 \\). Work out the total charge, \\( C \\), for a job that takes L hours in which the cost of materials and parts is \\( \\$ K \\). b) An airport currency exchange booth charges a fixed fee of \\( \\$ 10 \\) on all transactions and offer exchange rate of \\( \\$ 1 \\) to every 0.8 euros. Work out the total charge, \\( \\mathrm{C} \\), (in \\( \\$ \\) ) for buying \\( x \\) euros. c) A firm provides 5 hours of in-house training for each of its semi-skill workers and 10 hours of training for each skilled workers. Work out the total number of hours, \\( H \\), if the firm employs a semi-skilled and b skilled workers. d) A car hire company charges \\$C a day together with additional \\$c per mile. Work out the total charge, \\( \\$ \\mathrm{X} \\), for hiring a car for \\( \\mathrm{d} \\) days and travelling \\( \\mathrm{m} \\) miles during that time. 1. Write down a formula for each situation: a) A plumber has a fixed call- out charge of \\( \\$ 80 \\) and has an hourly rate of \\( \\$ 60 \\). Work out the total charge, \\( C \\), for a job that takes L hours in which the cost of materials and parts is \\( \\$ K \\). b) An airport currency exchange booth charges a fixed fee of \\( \\$ 10 \\) on all transactions and offer exchange rate of \\( \\$ 1 \\) to every 0.8 euros. Work out the total charge, \\( \\mathrm{C} \\), (in \\( \\$ \\) ) for buying \\( x \\) euros. c) A firm provides 5 hours of in-house training for each of its semi-skill workers and 10 hours of training for each skilled workers. Work out the total number of hours, \\( H \\), if the firm employs a semi-skilled and b skilled workers. d) A car hire company charges \\$C a day together with additional \\$c per mile. Work out the total charge, \\( \\$ \\mathrm{X} \\), for hiring a car for \\( \\mathrm{d} \\) days and travelling \\( \\mathrm{m} \\) miles during that time