If four numbers are in AP such that their sum is 50 and greatest number is 4 times the least then find the numbers.
Answers
Answered by
11
n = 4
Last term = 4×first term
L = 4a -------(1)
Now,
S4 = 50
=> 4/2 [ a +L] = 50
=> 2 ( a+4a) = 50
=> 2*5a = 50
=> 10a = 50
=> a = 5
Now,
20 = a + 3d
=> 20 = 5 + 3d
=> 3d = 15
=> d = 5
First term = 5
Second term = 10
Third term = 15
Fourth term = 20
Last term = 4×first term
L = 4a -------(1)
Now,
S4 = 50
=> 4/2 [ a +L] = 50
=> 2 ( a+4a) = 50
=> 2*5a = 50
=> 10a = 50
=> a = 5
Now,
20 = a + 3d
=> 20 = 5 + 3d
=> 3d = 15
=> d = 5
First term = 5
Second term = 10
Third term = 15
Fourth term = 20
Similar questions