Find the discount if P2,000 is discounted for 6 months at 8% compounded quarterly

Using oxyacetylene welding method to weld a 3 ft. long seam in a 3/8 in. thick plate at a consumption rate of 9 cu. ft. /ft. of weld for oxygen and 7 cu. ft./ft. for acetylene. What is the total combined gas consumption in cu. ft.?

We are drilling a hole at a depth of 4,000 ft with an 8 ½ in bit and a mud weight of 15 ppg, where the formation is abnormally pressurised. Formation pressure is 2400 psi, therefore a casing should be run at 4,500 ft to seal off this formation. There are Grade C-75 and N-80 casings available, C-75 Grade is 20.00 lb/ft (ID=6.456”, OD=7”) and N-80 is 17.00 lb/ft (ID= 6.538”, OD=7”). Analyse if both, neither or one of the casing Grades can withstand the formation pressure and will not collapse at the reported conditions. Use the API formulas and tables