Let 1 16 , a and b be in G.P. and 1 a , 1   b , 6 be in A.P., where a , b > 0 . Then 72 ( a + b )…

Let 116,a and b be in G.P. and 1a,1 b,6 be in A.P., where a,b>0. Then 72(a+b) is equal to _______ .

Solution

a2=b161b=116a2

2b=1a+6

18a2=1a+6

1a2-8a-48=0

1a=12,-4a=112,-14

a=112,a>0

b=16a2=19

72(a+b)=6+8=14

Asked in: JEE Main 2021 (16 Mar Shift 2)

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