Question

Pls solve 27th question

Answer 1

given,

A- 1,8,15......1975

d1- 7

B-2,13,24.....1882

d2-11

Now,

d(common)-LCM(d1,d2)-(7,¹1) -77

Here,the first common term will be 57

In order to find the number of common terms between the two series, we write the inequality

57+(n-1)77<1975

(n-1)77<1918

(n-1)<(1918/77)

(n-1)<24.9

n=25.9

n=25

57+(n-1)77<1982

(n-1)77<26

n= 25

so, the first common term of the series is 57

and the last one is

57+(25-1)77

57+24×77

1905