1. After paying 30 out of 40 installments of adebt of Rs. 3600/-, one

1.	1. After paying 30 out of 40 installments of adebt of Rs. 3600/-, one third of the dept isunpaid. If the installments are forming an A.P.Then what is the first installment.(a) Rs. 50/- (b) Rs. 51/.(c) Rs. 105/- (d) Rs. 110/-
Answer» Let the first term/instalment = Rsa. Let the common difference between successive instalment = Rsd Istcase:A man pays off a debt of Rs 3600 in 40 annual instalments ∴n= 40 and Sn= S40= Rs 3600Sn=n/2(2a+(n-1)d)S40=40/2(2a+39d)3600=20(2a+39d)2a+39d=180...(1)IIndcase:Man dies, leaving one-third of the debt unpaid. Now debt unpaid1/3*3600=1200∴ Debt paid by Man in 30 instalments = Total debt paid – Debt unpaid = 3600 – 1200 = Rs 2400 Heren= 30 and Sn= S30= 2400 S30=30/2(2a+29d)160=2a+29d2a+28d=60 Subtracting equation (2) from equation (1), we get (2a+ 39d) – (2a+ 29d) = 180 – 160 ⇒39d– 29d= 20 ⇒10d= 20 ⇒d= 2 Putting value ofdin (1), we get 2a+ 39d= 180 ⇒2a+ 39 × 2 = 180 ⇒2a= 180 – 78 2a= 102 ⇒a= 51 Rs Therefore, the first instalment paid by man = Rs 51 Th Thanks take weights of five ofyour friends. find out what their weights will be on the moon and the mars.

1. After paying 30 out of 40 installments of adebt of Rs. 3600/-, one third of the dept isunpaid. If the installments are forming an A.P.Then what is the first installment.(a) Rs. 50/- (b) Rs. 51/.(c) Rs. 105/- (d) Rs. 110/-

Answer»

Let the first term/instalment = Rsa.

Let the common difference between successive instalment = Rsd

Istcase:A man pays off a debt of Rs 3600 in 40 annual instalments

∴n= 40 and Sn= S40= Rs 3600Sn=n/2(2a+(n-1)d)S40=40/2(2a+39d)3600=20(2a+39d)2a+39d=180...(1)IIndcase:Man dies, leaving one-third of the debt unpaid.

Now debt unpaid1/3*3600=1200∴ Debt paid by Man in 30 instalments = Total debt paid – Debt unpaid

= 3600 – 1200 = Rs 2400

Heren= 30 and Sn= S30= 2400

S30=30/2(2a+29d)160=2a+29d2a+28d=60

Subtracting equation (2) from equation (1), we get

(2a+ 39d) – (2a+ 29d) = 180 – 160

⇒39d– 29d= 20

⇒10d= 20

⇒d= 2

Putting value ofdin (1), we get

2a+ 39d= 180

⇒2a+ 39 × 2 = 180

⇒2a= 180 – 78

2a= 102

⇒a= 51 Rs

Therefore, the first instalment paid by man = Rs 51

Thanks

take weights of five ofyour friends. find out what their weights will be on the moon and the mars.