Answer:
90
Explanation:
We have three students
Let the score of the First student be represented as = A
Let the score of the Second Student be represented as = B
Let the score of the Third Student be represented as = C
The sum of the three is 217
Therefore:
A+B+C = 217 .........Equation 1
If the first is 30 points more than the the second
Therefore,
A= 30 + B
A - B = 30 ..........Equation 2
The sum of the first two is 16 more than twice the third
A+B = 16 + 2(C)
A+B = 16 + 2C ............ Equation 3
Therefore substitute 16 + 2C for A+B in Equation 1
A+B+C = 217...... Equation 1
Hence, 16+2C+C = 217
16 + 3C = 217
3C = 217 - 16
3C = 201
C = 201 ÷ 3
C = 67
The score of the third(third student) = 67
The next step would be to substitute 67 for C in Equation 1
A+B+C = 217...... Equation 1
A+B+ 67 = 217
A+ B = 217 - 67
A+B = 150
A+B = 150 ........... Equation 4
Therefore, we combined Equation 2 and Equation 4
A - B = 30 ..........Equation 2
A+B = 150 ........... Equation 4
We would use the Elimination method
2A = 180
A = 180÷2
A = 90
Therefore the first score (for the first student ) = 90