A. 170 students out of the 230 students love both biking and skating (to make it easier, the percentage is about 0.74).
I am sorry if I cannot solve the other half of your question
Try this solution:
1. for probability of both televisions work:

2. for probability of at least on is defective (it means, the sum = one is defective and two are defective):
- for P(1defective);
- for P(2defective);
totaly for at least one is defective:

Answer:
∧ABC ≈ ∧PQR Angle-Angle Similarity Postulate
∧ ABC ≈ ∧ DEF Side-Side-Side Similarity Postulate
Step-by-step explanation: