Labor cost

dear sir please help me how can calculate this case: Eclipse ltd operates a factory that employed 40 direct workers throughout the four week period just ended. Direct employees were paid at a basis rate of 4$ per hour for a 38 hour week. Total hours of the direct worker in the four week in the four week period were 6,528 overtime, which is paid at a premium at 35% , is worked in order to meet general production requirements, 188 hours of direct workers time were worker's time were registered as idle employee and employer's deduction for National Insurance Contribution total 20% and 30% of gross wages respectively calculate a. the total labour cost to be paid for the period lcv b the total direct and indirect labour cost i calculate follow: over time: 6528 - (38 x 4 x 40)=448 basic pay: 6528 x 4 =26112 overtime: 448 x 4 x 35%= 627.2 idle time: 188 x 4 = 752 gross pay : 27491.2 NIC employer : 20% = 5498.24 total labour cost : 32,989.44 my number is incorrect -> how can calculate a and b