Question

Four chairs and 3 tables cost 2100 and 5 chairs and 2 tables cost 1750. Find the cost of one chair and one table ?

Answer 1

Let the cost of 1 chair be x and cost of 1 table be y  

According to the question,  

4x + 3y = 2100 ....... (Eqn 1)  

5x + 2y = 1750 ........... (Eqn 2)  

Multiplying (eqn 1) by 2 and (Eqn 2) by 3,  

8x + 6y = 4200 ......... (Eqn 3)  

15x + 6y = 5250 ......... (Eqn 4)  

(Eqn 4) - (Eqn 3)  

7x = 1050  

x = 1050 ÷ 7  

x = 150  

Substituting the value of x in (Eqn 1)  

y = 500  

Cost of chair = 150  

Cost of table = 500  

Answer 2

ᴀʜᴏʏ ᴍᴀᴛᴇ!

　　
　　

ʟᴇᴛ ᴜs ᴛᴀᴋᴇ ᴛʜᴀᴛ,

ᴄᴏsᴛ ᴏғ 1 ᴋɢ ᴏғ ᴀᴘᴘʟᴇs ʙᴇ x
ᴄᴏsᴛ ᴏғ 1 ᴋɢ ᴏғ ɢʀᴀᴘᴇs ʙᴇ ʏ

ᴛʜᴇɴ ᴛʜᴇ ᴀʟɢᴇʙʀᴀɪᴄ ʀᴇᴘʀᴇsᴇɴᴛᴀᴛɪᴏɴ ᴄᴀɴ ʙᴇ ᴅᴏɴᴇ ᴀs,

2x + ʏ = 160 - - - - - - - - - - - - - ①
　　
　　
4x + 2ʏ = 300 - - - - - - - - - - - - ②