Question

The teacher tells the class that the highest Mark's obtained by a student in her class is twice the lowest Mark's plus 7. The highest mark is 87. What is the lowest mark?

Answer 1

let take lowest mark X.

highest marks is = (2X)+7

Highest mark obtain in the class is 87

hence,

87= 2X + 7

87 - 7 = 2X

80 = 2X

80/2 = X

the answer to the question is 40 marks.

Answer 2

Answer:

ʟᴇᴛ ᴛʜᴇ , ʟᴏᴡᴇꜱᴛ ꜱᴄᴏʀᴇ ʙᴇ 'x'..

∴ ʜɪɢʜᴇꜱᴛ ꜱᴄᴏʀᴇ ᴏʙᴛᴀɪɴᴇᴅ ʙʏ ᴀ ꜱᴛᴜᴅᴇɴᴛ = 2x + 7

ɴᴏᴡ , ᴀᴄᴄᴏʀᴅɪɴɢ ᴛᴏ Qᴜᴇꜱᴛɪᴏɴ

2x + 7 = 87

ᴛʀᴀɴꜱᴘᴏꜱɪɴɢ 7 ꜰʀᴏᴍ ʟʜꜱ ᴛᴏ ʀʜꜱ , ᴡᴇ ɢᴇᴛ

ᴅɪᴠɪᴅɪɴɢ ʙᴏᴛʜ ꜱɪᴅᴇꜱ ʙʏ 2 , ᴡᴇ ɢᴇᴛ

⇒ 2x / 2 = 80/2 ⇒ x = 40

ʜᴇɴᴄᴇ , ᴛʜᴇ ʟᴏᴡᴇꜱᴛ ꜱᴄᴏʀᴇ ɪꜱ 40 .