Question

Ramkali saved rs 5 in the first week of the year and then increased her weekly saving by 1.75 rs .if the nth term of week , her weekly saving become 20.75 rs , find n.

Answer 1

let a be rs 5
d = 1.75
an = 20.75
find n

we know,
an = a + (n-1)d
20.75 =5 + 1.75n - 1.75
17.5 = 1.75n
n = 10
:)

Answer 2

$\huge\mathfrak{Bonjour!!}$

$\huge\fcolorbox{black}{aqua}{Solution:-}$

✒ ᴀɴsᴡᴇʀ:-

⛄ ʀᴀᴍᴋᴀʟɪ's ᴡᴇᴇᴋʟʏ sᴀᴠɪɴɢs ᴡɪʟʟ ʙᴇ ʀs. 20.75 ɪɴ 10ᴛʜ ᴡᴇᴇᴋ.

✒sᴛᴇᴘ-ʙʏ-sᴛᴇᴘ ᴇxᴘʟᴀɴᴀᴛɪᴏɴ:-

⛄sᴜᴘᴘᴏsᴇ ʀᴀᴍᴋᴀʟɪ's ᴡᴇᴇᴋʟʏ sᴀᴠɪɴɢs ᴡɪʟʟ ʙᴇ ʀs. 20.75 ɪɴ ᴛʜᴇ ɴᴛʜ ᴡᴇᴇᴋ.

★ ᴄʟᴇᴀʀʟʏ, ʀᴀᴍᴋᴀʟɪ's ᴡᴇᴇᴋʟʏ sᴀᴠɪɴɢs ғʀᴏᴍ ᴀ.ᴘ. ᴡɪᴛʜ ғɪʀsᴛ ᴛᴇʀᴍ ᴀ=5 ᴀɴᴅ ᴄᴏᴍᴍᴏɴ ᴅɪғғᴇʀᴇɴᴄᴇ ᴅ= 1.75.

ᴛʜᴇʀᴇғᴏʀᴇ,

ɴᴛʜ ᴛᴇʀᴍ = 20.75

=> ᴀ + (ɴ - 1)ᴅ = 20.75

=> 5 + (ɴ-1) × 1.75 = 20.75

=> (ɴ - 1) × 1.75 = 15.75

=> ɴ -1 = 15.75/1.75

=> ɴ - 1 = 9

=> ɴ = 10

ʜᴇɴᴄᴇ, ʀᴀᴍᴋᴀʟɪ's ᴡᴇᴇᴋʟʏ sᴀᴠɪɴɢs ᴡɪʟʟ ʙᴇ ʀs. 20.75 ɪɴ 10ᴛʜ ᴡᴇᴇᴋ.

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