The probability of answering a question correctly is $\dfrac{2}{5}$ and probability of not answering the same question correctly is $\dfrac{x}{15}$. The value of x is :

1. 6

2. 9

3. 15

4. 5

The sum of two angles of a triangle is equal to its third angle. Then the triangle is :

1. isosceles only

2. right-angled only

3. equilateral

4. isosceles right-angled

In the given figure, ac = y units, BC = x units, then the height of DC is :

1. $\sqrt{x + y}$

2. $\sqrt{xy}$

3. $\sqrt{y - x}$

4. $\sqrt{\dfrac{y}{x}}$

A man invests ₹ 11,000 in ₹ 100 shares paying 10% dividend. If his annual income from these shares is ₹ 1,000, then the market value of each share is :

1. ₹ 100

2. ₹ 120

3. ₹ 110

4. ₹ 220