Question

3. Aman spends rs.100 on screws costing 40 paise per dozen and rs.50 on screws costing 50 paise
per dozen, what is the average cost per dozen?
[Ans. 43 paise per dozen] explain full steps. please
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Answer 1

1st case :

Cost of screw per dozen in 1st case= 40 paise

Total cost of screws which worth 40 paise = Rs.100 = 100 * 100 = 10000 paise (since 1 rupee=100 paise)

Here to know the number of dozens that cost 40 paise we need to divide total cost by Cost per dozen

That is Number of dozens which cost 40 paise = 10000/40 = 250 dozens

2nd case :

Cost of screw per dozen in 2nd case= 50 paise

Total cost of screws which worth 40 paise = Rs.50 = 50 * 100 = 5000 paise (since 1 rupee=100 paise)

Here to know the number of dozens that cost 50 paise we need to divide total cost by Cost per dozen

That is Number of dozens which cost 50 paise = 5000/50 = 100 dozens

Total cost of screws = Rs.100 + Rs.50

= 10000 paise + 5000 paise (since the answer is in paise)

= 15000 paise

Total number of dozens = Number of dozens which cost 40 paise + Number of dozens which cost 50 paise

= 250 dozens + 100 dozens

= 350 dozens

Average cost per dozen = Sum of observations/Number of observations

=Total cost of screws/Total number of dozens

= 15000/350

= 1500/35

= 300/7

$= 42 \frac{6}{7}$

= 42.86..

= 43 paise (approximately)

Hope it helps you....