1.

The sum of the first three terms of an AP is 30 and the ratio of second and the third number is 2:3. Then the ratio of the first and the third number is *​

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: 7Let US assume the 3 numbers which are in A.P. are, a−d,a,a+dNow adding 3 numbers =a−d+a+a+d=303a=30a=30/3a=10 Given ratio 3:7=a−d:a+d3/7=(a−d)/(a+d)(a−d)7=3(a+d)7a−7d=3a+3d7a−3a=7d+3d4a=10d4(10)=10d40=10dd=40/10d=4 THEREFORE, the numbers are a−d=10−4=6a=10a+d=10+4=14So,6,10,14,… are in A.P.



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