Jawapan

2016-03-19T09:24:55+08:00
2016-03-19T09:27:41+08:00
At first Emma has 53 marble , she gets some marble from Fred , but she don't know how much it is. after that she gives Tessie 10 marble . at last she has 58 marble more. so ,

53-10=43
58-43=15
so, Fred gives Emma 15 marble because after she give 10 marble to Tessie she still remain 58 marbles.