Let x equal the number of adult tickets sold.
X + 3X=512
(I put 3x because we know the students sold 3 times as many).
Solve for X.
X+3X=512
4X=512
4X/4=512/4
X=128
Gavin needs $80 to buy a fish tank. He has saved $8 and plans to work as a babysitter to earn $9 per hour. Which inequality shows the minimum number of hours, n, that Gavin should work as a babysitter to earn enough to buy the fish tank? 8 + 9n ≥ 80, so n ≥ 8 8 + 9n ≤ 80, so n ≤ 8 9n ≥ 80 + 8, so n ≥ 9.8 9n ≤ 80 + 8, so n ≤ 9.8
Step-by-step explanation:

Answer:
Proved,
P(A∪B)=0.72
Step-by-step explanation:
Sue travels by bus or walks when she visits the shops.
Probability( catch the bus to the shop ), P(A) = 0.4
Probability( catch the bus from the shop ), P(B) = 0.7
Both A and B are independent events.
Therefore,
P(A∩B) = 0.4×0.7
= 0.28
Probability Sue walks one way = 1 - P(A∩B)
= 1 - 0.28
= 0.72
Hence, the probability that Sue walks at one way is 0.72