Question

If a,b,c,d are in H.P then ab+bc+cd is equal to​

Answer 1

Answer:

Since a,b,c are in H.P, so b=

a+c

2ac

.

Also, b,c,d are in H.P, so c=

b+d

2bd

.

Therefore, (a+c)(b+d)=

b

2ac

×

c

2bd

⇒ab+cb+ad+cd=4ad

⇒ab+bc+cd=3ad