Which of these numbers is not divisible by 9?

1. 729

2. 486

3. 634

4. 891

If A = {3, 6, 9, 12}, then n(A) =

1. 3

2. 4

3. 6

4. 12

If 4 pens cost ₹ 60, how much would 7 pens cost?

1. ₹ 105

2. ₹ 100

3. ₹ 120

4. ₹ 140