ANSWER :
R24.40 each
EXPLANATION :
Thabo has twin sisters, so they are three.
Thabo is 10 years old
Each sister is 4 years old.
Their age ratio is 10 : 4 : 4 and R109.80 will be divided amongst them in that ratio.
Step 1 :
Add the ratios, 10 + 4 + 4 = 18
Step 2 :
Divide R109.80 by 18

Step 3 :
Multiply the result to their ratio :
10(6.1) : 4(6.1) : 4(6.1)
61 : 24.40 : 24.40
From here, we can say that his sister will receive R24.40 each