1. The problem statement, all variables and given/known data There are two planets called Alpha and Beta. mass of alpha=M mass of beta=0.01M They are distance R apart. At what distance, expressed in terms of R, from the planet Alpha, along a straight line joining the centres of Alpha and Beta, will the ratio of [force alpha : force beta] on an asteroid be equal to 8100? 2. Relevant equations I avoided the use of newtons universal theory of gravity since there are no actual numbers. i used ratios instead. 3. The attempt at a solution here goes... [mass (alpha)/distance (alpha)] / [mass (beta)/distance (beta)]=8100 let x be the distance between alpha and the asteroid. [M/xR] / [0.01M/(R-xR)]=8100 Simplify: [1-x/0.01x]=8100 Solve for x: x=0.012R but the answer is 0.909R!!! Thanks for your help.