50 books and 30 copies has been purchased from a student of a class if each book cost rs 70 and a copy cost rs 40 find the total amount of the purchased
Answers
Answered by
2
Answer:
Let the number of books be = x.
Total cost of the books = Rs. 60.
∴ Cost of each book =Rs.
x
60
If the number of books is (x + 5), then the cost of each book = Rs.
x+5
60
Difference in cost is one rupee = Cost of each book when number of books is (x) - Cost of each book when number of books is (x + 5)
x
60
−
x+5
60
=1
x(x+5)
60(x+5)−60x
=1
x
2
+5x
60x+300−60x
=1
x
2
+5x=300
x
2
+5x−300=0
x
2
+20x−15x−300=0
x(x+20)−15(x+20)=0
(x+20)(x−15)=0
x+20=0 or x−15=0
∴x=−20 or x=15
∴ Number of books = x = 15
Number of books cannot be negative. Hence, -20 is rejected.
∴ Cost of each book =
x
60
=
15
60
=Rs.4
Step-by-step explanation:
Answered by
1
Answer:
3500 books and 2800 is cost of copy
Similar questions