Cost of 4 pens, 6 notebooks and 9 files is Rs 305. Cost of 3 pens, 4 notebooks and 2 files is Rs 145. What is the cost (in Rs.) of 5 pens, 8 notebooks and 16 files ?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 ie 465.
Let the cost of pen be x.
Cost of notebook be y.
Cost of files be x.
4x + 6y + 9z = 305 eq1
3x + 4y + 2z = 145 eq2
multiplying eq1 by 2
8x + 12y + 18z = 610 eq3
eq3 - eq2
8x + 12y + 18z - (3x + 4y + 2z) = 465
5x + 8y + 16z = 465