Question 14 Fill the two blanks in the sequence 2, ____ , 26, ____ so that the sequence forms an A.P
Given AP
2, ____ , 26, ____
Here,
First term = a = 2
Third term = a3 = 26
We need to find a2 and a4
Now,
an = a + (n – 1)d
a3 = a + (3 – 1)d
a3 = a + 2d
Putting values
26 = 2 + 2d
26 – 2 = 2d
24 = 2d
24/2 = d
12 = d
d = 12
Now,
a2 = a + (2 – 1)d
a2 = a + d
Putting values
a2 = 2 + 12
a2 = 14
a4 = a + (4 – 1)d
a4 = a + 3d
Putting values
a4 = 2 + 3 × 12
a4 = 2 + 36 = 38
So, our answer is
2, 14 , 26, 38

CBSE Class 10 Sample Paper for 2020 Boards - Maths Standard

Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 10 years. He provides courses for Maths and Science at Teachoo.