Answer:
12 bikes
9 tricycles
Step-by-step explanation:
x+y=21
2x+3y=51
x=-y+21
2(-y+21)+3y=51
-2y+42+3y=51
y+42=51
y=9
x=12
Answer: The test contains 10 three-point questions and 14 five-point questions.
Step-by-step explanation:
Let x represent the number of 3-point questions.
Let y represent the number of 5-point questions.
The maths test consists of 24 questions. This means that
x + y = 24
Each question is worth either 3 points or 5 and the test is worth 100 points. This means that
3x + 5y = 100 - - - - - - - - - - -1
Substituting x = 24 - y into equation 1, it becomes
3(24 - y) + 5y = 100
72 - 3y + 5y = 100
- 3y + 5y = 100 - 72
2y = 28
y = 28/2 = 14
Substituting y = 14 into x = 24 - y , it becomes
x = 24 - 14 = 10
