Question

find the 10 term whoes 5 term is 24 and difference between 7 term and 10 term is 15​

Answer 1

Answer:

Given A.P is

−40,−15,10,35,.....

first term of this A.P is a

1

=−40

second term of this A.P is a

2

=−15

common difference of an A.P is given by

(i.e.,d=a

n+1

−a

n

)

putting n=1 in above equation

d=a

2

−a

1

=−15−(−40)=25

hence common difference for this A.P is d=25

the nth term of an A.P is given by.

a

n

=a

1

+(n−1)d

⟹a

n

=−40+(n−1)(25)

⟹a

n

=−40+25n−25

⟹a

n

=−65+25n....eq(1)

for finding 10th term (a

10

)of this A.P put n=10 in above eq(1)

⟹a

10

=−65+25×10

⟹a

10

=−65+250

⟹a

10

=185