(900-2×270)÷(5-2)
=360÷3
= 120 the number of notebooks is now calculated by the method of chickens and rabbits in the same cage.
270 ÷ (2+ 1) = 90.
270-90= 180 number of pencil cases, 1, ordinary pencils and fountain pens: (4*2+7)/(2+ 1)=5 yuan.
Suppose all notebooks: 2*270=540 yuan.
900-540=360 yuan
Pencil and fountain pen ***360/(5-2)= 120.
Notebook: 270- 120= 150.
Pen: 120/( 1+2)=40.
Pencil: 120-40=80, 1. Pencil and pen are: (4*2+7)/(2+ 1)=5 yuan.
Suppose all notebooks: 2*270=540 yuan.
900-540=360 yuan
Pencil and fountain pen ***360/(5-2)= 120.
Notebook: 270- 120= 150.
Pen: 120/( 1+2)=40.
Pencils: 120-40=80.
(4+4+7) ÷ 3 = 5 yuan regards pencil boxes and fountain pens as commodities, with an average of one 5 yuan.
, 1, kid, this can't even be 0. How can you solve the math problem in the fourth grade of primary school in a hurry?
In order to give prizes to the school sports meeting, the school bought pencils, notebooks and fountain pens ***270, and * * * spent 900 yuan, of which the number of pencil boxes was twice that of fountain pens. As we all know, how much did you buy for the pencil case 4 yuan, the notebook 2 yuan and the fountain pen 7 yuan?