a) How to draw the implied stair-case demand and supply curves? b) If the equilibrium price is $6 per driveway how many households would like their driveways shovelled and how many teenagers will be willing to shovel driveways?

Here -

The consumer's surplus is the difference between the price consumers is willing to pay and the equilibrium price.

Consumer's surplus for the first person #=14-6=8#
Consumer's surplus for the second person #=12-6=6#
Consumer's surplus for the third person #=10-6=4#
Consumer's surplus for the fourth person #=8-6=2#
Consumer's surplus for the fifth person #=6-6=0#

Total Consumer's surplus is #=8+6+4+2+0=$.20#

The worker's surplus is the difference between the equilibrium price and the price teenager is willing to accept.

Worker's surplus for the first person #=6-2=4#
Worker's surplus for the second person #=6-3=3#
Worker's surplus for the Third person #=6-4=2#
Worker's surplus for the fourth person #=6-5=1#
Worker's surplus for the fifth person #=6-6=0#

Total Worker's surplus #=4+3+2+1+0=$10#

How much do households actually pay to have their driveways shovelled?

Households actually pay to have their driveways shovelled #= 5 xx $6=$.30#

What is the value of household's total willingness to pay?
The value of household's total willingness to pay#=14+12+10+8+6=$50#