If matrix A of order 2 × 1 and matrix B of order 2 × 2 are added, then the order of the matrix A + B is:

1. 2 × 2

2. 2 × 1

3. 1 × 2

4. A + B is not possible

In the adjoining diagram, PQ is a tangent at A to the circle with centre O. If ∠OAC = 25°, then ∠ABC is:

1. 20°

2. 65°

3. 70°

4. 130°

A retailer purchased an air conditioner (A.C.) for ₹30,000. He marked up its price by 20% and then allows a discount of 10% on the marked price to a customer. If the sale is intra-state and the rate of GST is 28%, find the:

(a) marked price of A.C.

(b) total amount paid by the customer including GST.

(c) tax collected by the central and the state governments respectively.