The arithmetic mean and geometric mean between two numbers is
related as A.M : G.M= 5:4. If the difference between geometric mean
and harmonic mean is – 4/5 then find the two numbers.
Answers
Answer:
First Part,
Let a and b be two numbers.
According to question,
2
a+b
=5⟹a+b=10.....................(i)
ab
=4⟹ab=16.........................(ii)
Now, H.M between a and b=
a+b
2ab
=
10
2×16
=
5
16
Or,
Let a be first term and d be the common difference of corresponding A.P.
a+2d
1
=1.............(i)
a+4d
1
=−5....................(ii)
Solving both equations , we get
a=7 and d=−3
Now, t
10
=
a+9d
1
=
7+9×(−3)
1
=−
20
1
Answer:
ANSWER :
* First Part,
Let a and b be two numbers.
According to question,
2
a+b
=5⟹a+b=10.....................(i)
ab
=4⟹ab=16.........................(ii)
Now, H.M between a and b=
a+b
2ab
=
10
2×16
=
5
16
Or,
Let a be first term and d be the common difference of corresponding A.P.
a+2d
1
=1.............(i)
a+4d
1
=−5....................(ii)
Solving both equations , we get
a=7 and d=−3
Now, t
10
=
a+9d
1
=
7+9×(−3)
1
=−
20
1