Question

Two A.P.'s have the same common difference. The difference between each of first 5 successi terms of 1" A.P. is 5. What is the difference between each of last 10 successive terms of 2nd A.P.?​

Answer 1

Answer:

150

Step-by-step explanation:

For first A.P

S1

n

=(

2

n

)(2n+(n−1)d)

S1

30

=(

2

30

)(2×3+(30−1)d)

S1

30

=15(6+29d)

S1

30

=90+435d

For second AP

S2

n

=(

2

n

)(2n+(n−1)d)

S2

30

=(

2

30

)(2×8+(30−1)d)

S2

30

=15(16+29d)

S2

30

=240+435d

Difference between S1

30

−S2

30

=(90+435d)−(240+435d)=150