Question

For positive real numbers SS and KK, the function HK(S)H_K(S) is defined as:
HK(S)=max⁡(S−K,0)H_K(S) = \max(S - K, 0). The max⁡\max function is defined as:

max⁡(a,b)={a,when a>bb,when a≤b\max(a, b) = \begin{cases} a, & \text{when } a > b \\ b, & \text{when } a \le b \end{cases}

The graph below shows the plot of a function N(S)N(S) versus SS.

N(S)N(S) can be expressed as _____.

Plot of N(S) versus S for S from 0 to 30: N(S) is 0 for 0 <= S <= 10, increases linearly from 0 at S=10 to 10 at S=20, and remains constant at 10 for 20 <= S <= 30.
Choose one option
Official answer and solution
Official answer
A
From
Official GATE 2026 answer key

Solution

Evaluate each piecewise-linear combination of ramp functions HK(S)=max⁡(S−K,0)H_K(S) = \max(S - K, 0) over the intervals [0,10][0, 10], [10,20][10, 20], and [20,30][20, 30].

From the plot, N(S)N(S) is defined piecewise by:

N(S)={0,0≤S≤10S−10,10<S≤2010,S>20N(S) = \begin{cases} 0, & 0 \le S \le 10 \\ S - 10, & 10 < S \le 20 \\ 10, & S > 20 \end{cases}

Testing H10(S)−H20(S)=max⁡(S−10,0)−max⁡(S−20,0)H_{10}(S) - H_{20}(S) = \max(S - 10, 0) - \max(S - 20, 0):

  • For 0≤S≤100 \le S \le 10: 0−0=00 - 0 = 0.
  • For 10<S≤2010 < S \le 20: (S−10)−0=S−10(S - 10) - 0 = S - 10.
  • For S>20S > 20: (S−10)−(S−20)=10(S - 10) - (S - 20) = 10.

Thus N(S)=H10(S)−H20(S)N(S) = H_{10}(S) - H_{20}(S).

Final answer

Option (A)

The answer is the one in the official GATE answer key. The solution is this site's own explanation.

Source

Paper
GATE 2026 Computer Science and Information Technology - Session 1 (CS1)
Question
8 of 65
Section
General Aptitude

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