Answer:
Martha is wrong.
Step-by-step explanation:
Let the cost of the house is C.
Payment by Ranee = 40% of the cost
=40% of C
=
=0.40 C
Payment by Susan = 0.35 of the cost
=0.35 C
Combined payment by Ranee and Susan = 0.40C + 0.35C=0.75C
The remaining payment will be done by Martha.
So, the remaining payment = C- 0.75C=0.25 C
Hence, Martha will have to pay 0.25 of the cost or 25% of the cost.
So, Martha is wrong.