Question

which number should be subtracted from each of the numbers 13, 25 ,55 so that resulting number would be in continued proportion??​

Answer 1

(25-x)/(13-x) = (55-x)/(25-x)

Cross multiplying gives

625–50x+x^2 = 715–68x+x^2

18x=90

X=5

And indeed subtracting 5 from the original numbers gives: 8,20,50 which have constant ratio 2.5 (ie they are an geometric sequence)