15. M/s. A is providing mobile phones and Wi-Fi services in the country. M/s. B and M/s. C are other similar service providers already in operation. In competitive landscape, M/s. B and M/s. C decided to merge with each other. Such merger was an unexpected development in the industry. M/s. A decided to cope-up with such eventuality by intense review of its strategy and to form a core group to handle the situation. The situation where intense review of strategy is needed due to merger between M/s. B and M/s. C, indicates towards which type of strategic control for M/s. A?

If $\displaystyle A = \{1, 2, 3, 4, 5\}$, $\displaystyle B = \{2, 4\}$ and $\displaystyle C = \{1, 3, 5\}$ then $\displaystyle (A - C) \times B$ is:

If $\displaystyle f(x)=x^2-5$, evaluate $\displaystyle f(3)$, $\displaystyle f(-4)$, $\displaystyle f(5)$, and $\displaystyle f(1)$.

Out of a group of $\displaystyle 20$ teachers in a school, $\displaystyle 10$ teach Mathematics, $\displaystyle 9$ teach Physics and $\displaystyle 7$ teach Chemistry. $\displaystyle 4$ teach Mathematics and Physics but none teach both Mathematics and Chemistry. How many teach Chemistry and Physics; how many teach only Physics?

If $\displaystyle A = \{1, 2, 3, 4, 5, 7, 8, 9\}$ and $\displaystyle B = \{2, 4, 6, 7, 9\}$ then how many proper subset of $\displaystyle A \cap B$ can be created?

The number of subsets of the set $\displaystyle \{0, 1, 2, 3\}$ is:

If $\displaystyle f(x) = x^2+x-1$ and $\displaystyle 4f(x) = f(2x)$, then find the value of 'x'.