Question

The population of a village was decreasing every year due to migration, poverty and unemployment. The present population of the village is 315840. Last year the migration was 4% and the year before last, it was 6% What was the population of the village 2 years ago? ​

Answer 1

ANSWER ⤵️

Suppose there was x population two years ago.

Now,

the population migrated a year ago was 6%  i.e. 0.06

hence, the population left was

x  - (o.o6)x  suppose this with a variable as y

thus, x  - (o.o6)x=y

Now, population left was y. But again this year 4% people i.e. 0.04 migrated.

Hence, present population left was  

y - (0.04)y

Y{1- 0.04}= y {0.96}

But, acc' to the question, the present population is 315840.

Thus,  y{0.96}= 315840

substituting value of y in terms of x. we get,

x{1-0.06}{0.96}= 315840

x  * 0.94*0.96= 315840

solving this we get,

X= 3,50,000.

Thus, population two years ago was 3,50,000.

$☺️☺️$

Answer 2

Answer:

sᴜᴘᴘᴏsᴇ ᴛʜᴇʀᴇ ᴡᴀs x ᴘᴏᴘᴜʟᴀᴛɪᴏɴ ᴛᴡᴏ ʏᴇᴀʀs ᴀɢᴏ.

ɴᴏᴡ,

ᴛʜᴇ ᴘᴏᴘᴜʟᴀᴛɪᴏɴ ᴍɪɢʀᴀᴛᴇᴅ ᴀ ʏᴇᴀʀ ᴀɢᴏ ᴡᴀs 6% ɪ.ᴇ. 0.06

ʜᴇɴᴄᴇ, ᴛʜᴇ ᴘᴏᴘᴜʟᴀᴛɪᴏɴ ʟᴇғᴛ ᴡᴀs

x - (ᴏ.ᴏ6)x sᴜᴘᴘᴏsᴇ ᴛʜɪs ᴡɪᴛʜ ᴀ ᴠᴀʀɪᴀʙʟᴇ ᴀs ʏ

ᴛʜᴜs, x - (ᴏ.ᴏ6)x=ʏ

ɴᴏᴡ, ᴘᴏᴘᴜʟᴀᴛɪᴏɴ ʟᴇғᴛ ᴡᴀs ʏ. ʙᴜᴛ ᴀɢᴀɪɴ ᴛʜɪs ʏᴇᴀʀ 4% ᴘᴇᴏᴘʟᴇ ɪ.ᴇ. 0.04 ᴍɪɢʀᴀᴛᴇᴅ.

ʜᴇɴᴄᴇ, ᴘʀᴇsᴇɴᴛ ᴘᴏᴘᴜʟᴀᴛɪᴏɴ ʟᴇғᴛ ᴡᴀs

ʏ - (0.04)ʏ

ʏ{1- 0.04}= ʏ {0.96}

ʙᴜᴛ, ᴀᴄᴄ' ᴛᴏ ᴛʜᴇ ǫᴜᴇsᴛɪᴏɴ, ᴛʜᴇ ᴘʀᴇsᴇɴᴛ ᴘᴏᴘᴜʟᴀᴛɪᴏɴ ɪs 315840.

ᴛʜᴜs, ʏ{0.96}= 315840

sᴜʙsᴛɪᴛᴜᴛɪɴɢ ᴠᴀʟᴜᴇ ᴏғ ʏ ɪɴ ᴛᴇʀᴍs ᴏғ x. ᴡᴇ ɢᴇᴛ,

x{1-0.06}{0.96}= 315840

x * 0.94*0.96= 315840

sᴏʟᴠɪɴɢ ᴛʜɪs ᴡᴇ ɢᴇᴛ,

x= 3,50,000.

ᴛʜᴜs, ᴘᴏᴘᴜʟᴀᴛɪᴏɴ ᴛᴡᴏ ʏᴇᴀʀs ᴀɢᴏ ᴡᴀs 3,50,000.