Below is an instruction that describes a task. Write a response that appropriately completes the request in Swahili. Please answer in Swahili.

### Instruction:
George collected 50 marbles in white, yellow, green, and red. Half of them are white, and 12 are yellow. There are 50% fewer green balls than yellow balls. How many marbles are red?

### Response:
 Nusu ya mabulinge ni nyeupe, hivyo kuna mabulinge 50 / 2 = <<50/2=25>>25 nyeupe.
Mabulinge ya kijani ni 50% tu ya mabulinge ya njano, hivyo kuna mabulinge 50/100 * 12 = <<50/100*12=6>>6 ya kijani.
Hivyo kwa sasa tunajua kuwa tuna jumla ya mabulinge 25 + 12 + 6 = <<25+12+6=43>>43.
Yaliyobaki ni nyekundu, hivyo kuna mabulinge 50 - 43 = <<50-43=7>>7 nyekundu.