Question

A manufacturer of t.v sets produced 600 sets in the third year and 700 sets in the seventh year. Find 1 the production in the first year, 2 the production in the 10th year , 3 the total production in the first 7 year.
​

Answer 1

Step-by-step explanation:

ANSWER

 Let 'a' be the first term and 'd' be the common difference of the A.P formed  

a3=a+2d=600.................(i) 

And a7=a+6d=700......(ii)

Solving equation (i) and (ii)

a=550 and d=5

(i) Production in the first year is 550 TV sets.

(ii) Production in the 10th year = a10=a+9d

=550+9(25)

=550+225

=775

(iii) Total production in 7 years = 

S7=27[2(550)+(7−1)25]

=4375.

Thus, the total production in 7 years if of 7375 TV sets

Answer 2

Step-by-step explanation:

7375 is the answer.................