To the cinema 2

A cinema ticket costs 150 CZK for children and 200 CZK for adults. 100 tickets were sold for the film screening and the cashier collected 16,000 CZK. Calculate:
a. How many children's tickets were sold?
b. How much CZK was collected for adult tickets?
c. By what percentage is a children's ticket cheaper than an adult ticket?

Final Answer:

a =  80
d =  4000 Kc
c =  25 %

Step-by-step explanation:

$$\begin{gathered} 150a+200b=16000 \\ a+b=100 \\ 150\cdot a+200\cdot b=16000 \\ Row2-\frac{1}{150}\cdot Row1\to Row2 \\ -0.33b=-6.67 \\ b=\frac{-6.66666667}{-0.33333333}=20 \\ a=\frac{16000-200b}{150}=\frac{16000-200\cdot 20}{150}=80 \\ a=80 \\ b=20 \end{gathered}$$

$d=200\cdot b=200\cdot 20=4000\text{Kc}$

$c=100\cdot \frac{200-150}{200}=25\%$

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