C.11 Sweets sold at a candy store

Sweets of 70 yen per piece are sold at a certain candy store.

If you buy the boxed assortment containing 12 pieces, box cost is 50 yen.

If you buy five or more boxes containing 12 pieces per box, all the prices of sweets will become a 10% discount.

Moreover, if you buy 11 or more boxes, the box cost from the 11th box will become half the sum.

I would like to buy 170 sweets now. 

I decided to buy them by boxes containing 12 pieces per box as many as possible.

Find the number of the box containing 12 piece in this case.

Moreover, find the number of sweets which are not in the box. 

Find total price.  





Answer
14 boxes
2 pieces
11310 yen