The average cost of a pencil is ₹8 and the average cost of an eraser is ₹4. The cost of 8 erasers, 4 pencils and 12 sharpeners are ₹148. The average cost of a sharpener is ₹ ______.
- A6.5
- B6
- C7
- D6.66
Solution & Step-by-step Explanation
Given:
Average cost of a pencil = ₹8
Average cost of an eraser = ₹4
Cost of 4 pencils = 4×8=₹32
Cost of 8 erasers = 8×4=₹32
Let the average cost of a sharpener be ₹s.
Cost of 12 sharpeners = 12s
According to the question:
Cost of 8 erasers+Cost of 4 pencils+Cost of 12 sharpeners=148
32+32+12s=148
64+12s=148
12s=148−64
12s=84
s=
12
84
=7
Thus, the average cost of a sharpener is ₹7.
Average cost of a pencil = ₹8
Average cost of an eraser = ₹4
Cost of 4 pencils = 4×8=₹32
Cost of 8 erasers = 8×4=₹32
Let the average cost of a sharpener be ₹s.
Cost of 12 sharpeners = 12s
According to the question:
Cost of 8 erasers+Cost of 4 pencils+Cost of 12 sharpeners=148
32+32+12s=148
64+12s=148
12s=148−64
12s=84
s=
12
84
=7
Thus, the average cost of a sharpener is ₹7.