Given: 2 tailors stitch a PPE suit in 36 hours Formula used: M1 × H1 / W1 = M2 × H2/ W2, where, M is number of workers, H is number of hours and W is work done Calculation: Let required number of hours be ‘H” According to question: 2 × 36 × 1/1 = 12 × H × 1 /13 ⇒ H = 6 × 13 = 78 hours