Linear Equations in Two Unknowns
The consulation fees charged to an elder and an adult by a doctor are $100 and $180 respectively .On a certain day , there were 37 patients and the total consulation fee was $4740 .How many adults consultedthe doctor on that day?
A. 12
B. 13
C. 24
D. 25
F2 Maths
2013-03-14 2:31 am
回答 (2)
2013-03-16 4:30 am
✔ 最佳答案
The answer is B.
2013-03-14 3:47 am
Let the number of adults consulted the doctor on that day be x.
Then the number of elders consultedthe doctor on that day is (37-x)
100 x (37-x) + 180 x (x) = 4740
3700 - 100x + 180x =4740
80x = 4740 - 3700
x=13
The answer is B.
or
Let the number of adults consulted the doctor on that day be x.
And the number of elders consultedthe doctor on that day be y.
x + y =37.......(1)
180x + 100y = 4740.........(2)
From (1), we have:
y = 37-x....... (3)
Substitute (3) into (2), we have:
180x + 100(37 - x) = 4740
180x+ 3700 - 100x = 4740
80x = 1040
x=13
The answer is B.
Then the number of elders consultedthe doctor on that day is (37-x)
100 x (37-x) + 180 x (x) = 4740
3700 - 100x + 180x =4740
80x = 4740 - 3700
x=13
The answer is B.
or
Let the number of adults consulted the doctor on that day be x.
And the number of elders consultedthe doctor on that day be y.
x + y =37.......(1)
180x + 100y = 4740.........(2)
From (1), we have:
y = 37-x....... (3)
Substitute (3) into (2), we have:
180x + 100(37 - x) = 4740
180x+ 3700 - 100x = 4740
80x = 1040
x=13
The answer is B.
參考: me
收錄日期: 2021-04-13 19:21:00
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