 
 <translate> 20 of 50 marbles are white so there are 50 - 20 = 30 red and blue marbles. The number of red marbles and blue marbles is the same, so there are 30 / 2 = 15 of each color. The difference between the number of white marbles and blue marbles is 20 - 15 = 5. Double the difference is 5 * 2 = 10 marbles. 10 marbles are removed to leave 50 - 10 = 40 marbles. So the answer is 40. <hau> 20 daga 50 marbles ne fari haka akwai 50 - 20 = 30 ja da kuma blue marbles. Adadin jan marbles da shudi marbles iri daya ne, don haka akwai 30 / 2 = 15 na kowane launi. Bambanci tsakanin adadin farin marbles da blue marbles ne 20 - 15 = 5. Sau biyu bambanci shine 5 * 2 = 10 marbles. Ana cire marbles 10 don barin 50 - 10 = 40 marbles. Amsar ita ce 40. 