E & T Excavation Company is planning an investment of $425,700 for a bulldozer. The bulldozer is expected to operate for 2,000 hours per year for eight years. Customers will be charged $140 per hour for bulldozer work. The bulldozer operator costs $38 per hour in wages and benefits. The bulldozer is expected to require annual maintenance costing $20,000. The bulldozer uses fuel that is expected to cost $50 per hour of bulldozer operation.

Present Value of an Annuity of $1 at Compound Interest
Year	6%	10%	12%	15%	20%
1	0.943	0.909	0.893	0.870	0.833
2	1.833	1.736	1.690	1.626	1.528
3	2.673	2.487	2.402	2.283	2.106
4	3.465	3.170	3.037	2.855	2.589
5	4.212	3.791	3.605	3.352	2.991
6	4.917	4.355	4.111	3.784	3.326
7	5.582	4.868	4.564	4.160	3.605
8	6.210	5.335	4.968	4.487	3.837
9	6.802	5.759	5.328	4.772	4.031
10	7.360	6.145	5.650	5.019	4.192

Determine the net present value of the investment, assuming that the desired rate of return is 12%. Use the present value of an annuity of $1 table above. Round to the nearest dollar. If required, use the minus sign to indicate a negative net present value.

Present value of annual net cash flows	$
Less amount to be invested	$
Net present value	$

Determine the number of operating hours such that the present value of cash flows equals the amount to be invested. Round interim calculations and final answer to the nearest whole number. hours