A triangular direct runoff hydrograph due to a storm has a time base of 90 hours. The peak flow of $60 \mathrm{~m}^{3} / \mathrm{s}$ occurs at 20 hours from the start of the storm. The area of catchment is $300 \mathrm{~km}^{2}$. The rainfall excess of the storm (in $\mathrm{cm}$ ), is
(A) 2.00
(B) 3.24
(C) 5.40
(D) 6.48
A triangular direct runoff hydrograph due to a storm has a time base of 90 hours. The peak flow of $60 \mathrm{~m}^{3} / \mathrm{s}$ occurs at 20 hours from the start of the storm. The area of catchment is $300 \mathrm{~km}^{2}$. The rainfall excess of the storm (in $\mathrm{cm}$ ), is
(A) 2.00
(B) 3.24
(C) 5.40
(D) 6.48