Question

80% of 40 students are good at mathematics. How many are not good at mathematics?
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Answer 1

ʜᴇʟʟᴏ❤

ᴛᴏᴛᴀʟ sᴛᴜᴅᴇɴᴛs = 40

ᴘᴇʀᴄᴇɴᴛᴀɢᴇ ᴏғ sᴛᴜᴅᴇɴᴛs ɢᴏᴏᴅ ɪɴ ᴍᴀᴛʜs = 80%

ᴘᴇʀᴄᴇɴᴛᴀɢᴇ ᴏғ sᴛᴜᴅᴇɴᴛs ɴᴏᴛ ɢᴏᴏᴅ ɪɴ ᴍᴀᴛʜs = 100% - 80%

ᴘᴇʀᴄᴇɴᴛᴀɢᴇ ᴏғ sᴛᴜᴅᴇɴᴛs ɴᴏᴛ ɢᴏᴏᴅ ɪɴ ᴍᴀᴛʜs = 20%

ғɪɴᴅɪɴɢ ɴᴜᴍʙᴇʀ ᴏғ sᴛᴜᴅᴇɴᴛs ɴᴏᴛ ɢᴏᴏᴅ ɪɴ ᴍᴀᴛʜs

ʟᴇᴛ ᴛʜᴇ ɴᴜᴍʙᴇʀ ᴏғ sᴛᴜᴅᴇɴᴛs ɴᴏᴛ ɢᴏᴏᴅ ɪɴ ᴍᴀᴛʜs = x

ᴘᴇʀᴄᴇɴᴛᴀɢᴇ=

ɴᴜᴍʙᴇʀ ᴏғ sᴛᴜᴅᴇɴᴛs ɴᴏᴛ ɢᴏᴏᴅ ɪɴ ᴍᴀᴛʜs

__________________×100

20=x ×2.5

20

___

2.5 = x

8=x

x=8

8sᴛᴜᴅᴇɴᴛs ᴀʀᴇ ɴᴏᴛ ɢᴏᴏᴅ ɪɴ ᴍᴀᴛʜs

❥Tʜᴀɴᴋ Yᴏᴜ