

CBSE Class 10 Sample Paper for 2025 Boards - Maths Standard
CBSE Class 10 Sample Paper for 2025 Boards - Maths Standard
Last updated at Feb. 12, 2025 by Teachoo
Transcript
Question 36 [Case Based] Ms. Sheela visited a store near her house and found that the glass jars are arranged one above the other in a specific pattern. On the top layer there are 3 jars. In the next layer there are 6 jars. In the 3rd layer from the top there are 9 jars and so on till the 8th layer. The jars look like Question 36 (iii) (A) (iii) (A) If there are ‘n’ number of rows in a layer then find the expression for finding the total number of jars in terms of n. Hence find 𝑆_8 .Now, AP is 3, 6, 9, …. upto 8 terms We need to find Sn in terms of n. Now, Sn = 𝑛/2 [2a + [n − 1]d] Putting a = 3, d = 3 = 𝑛/2 [2(3) + [n − 1]3] = 𝑛/2 [6 + 3n − 3] = 𝒏/𝟐 [3 + 3n] Thus, Sn = 𝑛/2 [3 + 3n] We also need to find s8 Putting n = 8 in Sn S8 = 𝟖/𝟐 [3 + 3 × 8] = 4 [3 + 24] = 4 × 27 = 108