Answer:
Total number of days in the mines = 4.5 days + 3 days ≥ 7.5 days
Step-by-step explanation:
Requirement : 12 Ibs gold and 18 Ibs silver to pay monthly rent
Mine 1 ; 2 Ibs of gold , 2Ibs of silver.
Mine 2; 1 Ib of gold , 3 Ibs of silver
using LP
Gold : aX1 + bX2 ≥ 12 ---------- ( 1 )
Silver: cX1 + dX2 ≥ 18 --------- ( 2 )
where; X1 = days spent in Mine 1
X2 = days spent in Mine 2
Total days spent in mines : X1 + X2 =
a = Gold found in mine 1 = 2
b = Gold found in mine 2 = 1
c = silver found in mine 1 = 2
d = silver found in mine 2 = 3
Back to equations 1 and 2
2X1 + X2 ≥ 12 ----------- ( 3 )
2X1 + 3X2 ≥ 18 ------------ ( 4 )
solving equations 3 and 4
= 0 + 2X2 ≥ 6 ∴ X2 ≥ 3 days ( days spent in mine 2 )
Input value into ( 3)
2X1 ≥ 12 - 3 = 9
∴ X1 ≥ 4.5 days ( days spent in mine 1 )
Total number of days in the mines = 4.5 days + 3 days ≥ 7.5 days
