Question

given that 4, 12, x, y, 324, 972...... is a geometric sequence. find the sum of x and y.

Answer 1

Given that 4, 12, x, y, 324, 972...... is a geometric sequence

i) 12/4 = x/12

=> (12×12)/4 = x

=> 3×12 = x

=> x = 36

ii ) y/x = 12/4

=> y/36 = 3

=> y = 3×36

=> y = 108

Therefore,

x=36 ,y = 108

Sum of x and y = x + y

= 36 + 108

= 144

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