2021 · Q16
5 pencils, 6 notebooks and 7 erasers cost Rs. 250; whereas 6 pencils, 4 notebooks and 2 erasers cost Rs. 180. What is the cost of 2 notebooks and 4 erasers ?
Elementary MathematicsAlgebra
- ARs. 90
- BRs. 75
- CRs. 60
- DRs. 40
Explanation
Let p, n, e be the prices. From 5p + 6n + 7e = 250 and 6p + 4n + 2e = 180, eliminate p: 6 times the first minus 5 times the second gives 16n + 32e = 1500 − 900 = 600. Dividing by 8 yields 2n + 4e = 75. The cost of 2 notebooks and 4 erasers is Rs. 75, option (b).