It's 3 kilometers by car and 6 yuan.

Then take a bus for 8-3 = 5km, 14-6=8 yuan money.

The remaining15-3-5 = 7km, with 7 * 8/5 =1/.2 yuan money.

∴ A total of 6+8+ 1 1.2=25.2 yuan.

So my home is 15km away from my grandmother's home. I have 26 yuan with me, so it's enough to take a taxi to grandma's house.