A company produces an average of 4000 items per month for the first 3 months. How much items, it must produce on an average per month over the next 9 months to average 4375 items per month over the whole year?

(1) 4500 (2) 4600 (3) 4680 (4) 4710

Solution:

Let average production of a company in 9 months be x items

:. Accordingto question,

4375 = 3*4000*+9*x/12

or, 4375*12= 12*1000+ 9*x

:. 9*x = 12 (4375- 1000)

= 12*3375

:. x =12*3375/9 = 4500

Then the option is (1) 4500