A pen factory signed a contract to produce a number of souvenir pens for a company.
The pen company needs to produce pens in 5 days to accomplish the contract.
On the first day, it produced 1/5 of the required number of pens.
On the second day, it produced another 28 pens,
On the third day, it produced half of the number of pens produced on the first 2 days.
On the fourth day, it produced 9 more pens more than the first day.
On the fifth day, it completed the remaining 64 pens.
How many pens did the factory produce in those 5 days?
+313 Let the total pens produced in 5 days be x.
Pens produced on the first day = x/5
second day = 28
third day = (x/5 + 28)/2
4th day = x/5 + 9
5th day = 64
∴, x/5 + 28 + (x/5 + 28)/2
+ x/5 + 9 + 64
= x
=> x/5 + 1/2(x/5) + 1/2(28)
+ x/5 + 73 + 28 = x
=> x/5 + x/10 + x/5 + 101 + 14 = x
=> \( {2x + x + 2x \over 10} + 115 = x\)
=> \( {5x + 1150\over 10} = x\)
=> 5x + 1150 = 10x
=> 5x = 1150
=> x = 230
∴, total pens = \(\boxed{230}\)
