confusing statement: 'They were more in number than....'

defeated_soldier

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I bought 30 books on maths,phsics, and chemistry priced at rs 17,rs 19,and rs 23 per book respectively for distribution among poor students of standard X of a school. The physics books were more in number than the mathematics books but less than the chemistry books,the difference being more than one. The total cost amounted to rs 620 . How many books on mathematics ,physics and chemistry could have been bought respectively ?


please,look at above,

does it mean ...

no of phycis book - no of math books >1

and no of chemistry book-no of physics book >1

am i right ? is there more we can think of here ?

I am confused in this statement basically ..

CAN you please tell, how many inferences can be drawn on that bold colored statement ?
 
Re: confusing statement

defeated_soldier said:
no of phycis book - no of math books >1
and no of chemistry book-no of physics book >1
Yes your reading is correct.
We can get from that: 2p=35-3m, m+p+c=30, p>m+1 & c>p+1.
I found only one possible triple.
 
Re: confusing statement

defeated_soldier said:
I bought 30 books on maths,phsics, and chemistry priced at rs 17,rs 19,and rs 23 per book respectively for distribution among poor students of standard X of a school. The physics books were more in number than the mathematics books but less than the chemistry books, the difference being more than one. The total cost amounted to rs 620 . How many books on mathematics ,physics and chemistry could have been bought respectively ?

please,look at above,

does it mean ...

no of phycis book - no of math books >1

and no of chemistry book-no of physics book >1

am i right ? is there more we can think of here ?

I am confused in this statement basically ..

CAN you please tell, how many inferences can be drawn on that bold colored statement ?
From the given information, we can derive

1--M + P + C = 30 and
2--17M + 19P + 23C = 620
3--Multiplyinng (1) by 17 and subtracting from (2) yields P + 3C = 55
4--Solving for C we get C = (55 -- P)/3
5--Starting with P = 1, we derive
M...11...9...7...5...3...1
P....1....4...7..10.13.16
C..18..17.16..15.14.13

By inspection, only M = 5, P = 10 and C = 15 satisfy all the requirements.
 
Without the "the difference being more than one" condition, there is 2 solutions:
3,13,14 and 5,10,15
So it's evident the condition was put in to eliminate 3,14,15.
 
Re: confusing statement

defeated_soldier said:
I bought 30 books on maths,phsics, and chemistry priced at rs 17, rs 19, and rs 23 per book respectively for distribution among poor students of standard X of a school. The physics books were more in number than the mathematics books but less than the chemistry books, the difference being more than one. The total cost amounted to rs 620. How many books on mathematics, physics, and chemistry could have been bought respectively?

please, look at above....
Another way of backing into the answer is as follows:

1--M + P + C = 30
2--17M + 19P + 23C = 620
3--Multiplying (1) by 17 and subtracting from (2) yields P = 55 - 3C
4--By one quick calculation or inspection, C must be less than 18 (P = 55 - 54)
5--THerefore
C...17...16...15...14...13
P....4.....7....10...13...16
M...9.....7......5....2.....0
6--Since C - P > 1 and P - M > 1, M = 5, P = 10 and C = 15 is the only viable solution.
 
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