$(3)$

A contmetor has excavated a $4200$ m long trench with an average width of $2\mathrm{.}0$ m and long section as follows:

The following rates of payment are applicable:

Soft material

Soft material excavation, excavation depth $0$ to $1$ m below natural ground level: R $55$ per $m^3$

Soft material excavation, excavation depth $>1m$ to $2$ m below natural ground level: R$65$ per $m^3$

Intermediate material

Intermediate excavation, excavation depth $0$ to $1\mathrm{.}5$ m below natural ground level: R$75$ per m$3$

Intermediate excavation, excavation depth $>1\mathrm{.}5m$ to $3\mathrm{.}0$ m below natural ground level: R$85$ per $m{b}^3$

Hard material

Hard excavation, excavation depth $0$ to $1\mathrm{.}5$ m below natural ground level: R$110$ per $m^3$

Hard excavation, excavation depth exceeding $1\mathrm{.}5$ m below natural ground level: R$130$ per m$^3$

Calculate the payment due to the contractor for the excavation of the trench.

$(10)$