Question 531023
b = number of buses
v = number of vans
51b = number of people carried by each bus
8v = number of people carried by each van
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51b + 8v = 150 people being carried
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b + v = 8
so
v = 8-v
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substitute
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51b + 8(8-v) = 150
51b + 64 -8v = 150
43b = 86
b = 2
.
v = 8-b
v = 6
.
Check the total people carried.
51(2) = 102
8(6) = 48
102+48 = 150
Correct.
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Answer: They used 2 buses and 8 vans.
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Done.