We can measure the distance of a star that is 50 light years away using the parallax method. The star will be observed from two different locations on earth and by measuring the distance between both the locations and angle subtended by the star on both positions, the star distance can be calculated. This method cannot be used to measure a star which is more than 100 light years as the accuracy of the result is not achieved. Thus, we cannot measure the star 150 light years away from us using the same method.