Question

ramkali saved 5 in the first week of year and then increased her weekly saving by Rs 1.75.if in the bath week, her weekly saving become really 20.75,find n

Answer 1

Ramkali saved in 1st week = 5 ₹
and increase per week = 1.75₹

We absorb here,
5 , 6.75 , 8.5 ,.........20.75 are in AP
where, a = 5 , d = 1.75 and Tn = 20.75

Tn = a + ( n -1)d
20.75 = 5 + (n -1)1.75
15.75 = 1.75(n -1)
9 = n -1
n = 10


Hope it helps. Plz mark me as brainliest.

Answer 2

Answer:

Given that, Ramkali saved Rs.5 in the first week and then started increasing her savings each week by Rs.1.75.

Hence,

First term, a = 5

and common difference, d = 1.75

Also given,

an = 20.75

Find, n = ?

As we know, by the nth term formula,

an = a + (n − 1) d

Therefore,

20.75 = 5 + (n – 1) × 1.75

15.75 = (n – 1) × 1.75

(n – 1) = 15.75/1.75 = 1575/175

= 63/7 = 9

n – 1 = 9

n = 10

Hence, n is 10.