Answer:
(c) or 10 is the answer
Step-by-step explanation:
In order to find slope you have to follow the formula
(y2-y1) / (x2-x1)
That would give you the slope which in this case is 10.
Assigning "a" as cost of adult tickets and "c" the cost of children's tickets.
3a + 4c = 107
2a + 3c = 76
elimination method
2(3a + 4c = 107)
-3(2a + 3c = 76)
6a + 8c = 214
-6a - 9c = -228
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0 - c = - 14
c = 14
Then 2a + 3(14) = 76
2a = 76 - 42
2a = 34
a = 34/2
a = 17
Let the present age of student be x
Present of teacher will be 4x
After 20 years,
Age of student = x + 20
Age of teacher = 4x + 20
According to the given condition after 20 years,
x + 20 = (4x + 20)/2
x + 20 = 2x + 10
2x - x = 20 - 10
x = 10
So student's present age is 10 years while teacher's is 4 x 10 i.e 40 years.
Hope This Helps You!
