CASE STUDY QUESTION 24-Class X-Maths

CASE STUDY QUESTION 24-Class X-Maths

The production of TV sets in a factory increases uniformly by a fixed number every year. It produced 16000 sets in 6th year and 22600 in 9th year.

(i) Find the production during first year.
(a) Rs. 5000 (b) Rs. 2200 (c) Rs. 10000 (d)none of these

(ii) Find the production during 8th year
(a) Rs. 7200 (b) Rs. 22000 (c) Rs. 20400 (d)none of these

Production during 8th year is given by a₈
= (a + 7d)
= (5000 + 7(2200))
= (5000 + 15400)
= 20400.

(iii) Find the production during first 3 years.
(a) Rs. 21600 (b) Rs. 22000 (c) Rs. 20400 (d)none of these

a₂ = (a + d)
= (5000 + 2200) = 7200.
a₃ = (a2 + d)
= 7200 + 2200 = 9400.
Production during first 3 years = 5000 + 7200 + 9400 = 21600

(iv) In which year, the production is Rs. 29,200.
(a) 10 (b) 11 (c) 12 (d) 13

a_n = 5000 + (n – 1)2200 = 29200
(n – 1)2200 = 29200 – 5000 = 24200
⇒ n – 1 = 11
⇒ n = 12

(v) Find the difference of the production during 7th year and 4th year.
(a) Rs. 5000 (b) Rs. 2200 (c) Rs. 10000 (d)none of these

a₄ = (a + 3d)
= (5000 + 3(2200)) = 5000 + 6600 = 11600.
a₇ = (a6 + d)
= 16000 + 2200 = 18200.
Difference = 18200 – 11600 = 6600