Question

The sum of three number in A.P is 12 and the ratio of first number to third number is 1:3 find the number

Answer 1

Answer:

From the question, it is given that,

the sum of three numbers in A.P. =30

The ratio of the first number to the third number is 3: 7

Let us assume the 3 numbers which are in A.P. are, a−d,a,a+d

Now adding 3 numbers =a−d+a+a+d=30

3a=30

a=30/3

a=10

Given ratio 3:7=a−d:a+d

3/7=(a−d)/(a+d)

(a−d)7=3(a+d)

7a−7d=3a+3d

7a−3a=7d+3d

4a=10d

4(10)=10d

40=10d

d=40/10

d=4

Therefore, the numbers are a−d=10−4=6

a=10

a+d=10+4=14

So,6,10,14,… are in A.P.

Ok please mark brainiest