Question:medium

Suppose hospital A admitted 21 less Covid infected patients than hospital B, and all eventually recovered. The sum of recovery days for patients in hospitals A and B were 200 and 152, respectively. If the average recovery days for patients admitted in hospital A was 3 more than the average in hospital B then the number admitted in hospital A was

Updated On: Jan 15, 2026
Show Solution

Correct Answer: 35

Solution and Explanation

Let \( x \) be the number of patients admitted to hospital A, and \( x + 21 \) be the number of patients admitted to hospital B.

Given information:

  • Total recovery days for hospital A: 200
  • Total recovery days for hospital B: 152
  • Average recovery days for hospital A is 3 days more than for hospital B.

Step 1: Formulate the Equation

Average recovery days for hospital A = \( \frac{200}{x} \)

Average recovery days for hospital B = \( \frac{152}{x + 21} \)

The problem states that the average for hospital A exceeds the average for hospital B by 3 days. This yields the equation:

\[ \frac{200}{x} = \frac{152}{x + 21} + 3 \]

Step 2: Solve the Equation

Isolate the terms with \( x \):

\[ \frac{200}{x} - \frac{152}{x + 21} = 3 \]

To eliminate the denominators, multiply both sides by \( x(x + 21) \):

\[ 200(x + 21) - 152x = 3x(x + 21) \]

Expand both sides of the equation:

\[ 200x + 4200 - 152x = 3x^2 + 63x \]

Combine like terms:

\[ 48x + 4200 = 3x^2 + 63x \]

Rearrange into a standard quadratic form \( ax^2 + bx + c = 0 \):

\[ 3x^2 + 15x - 4200 = 0 \]

Apply the quadratic formula: \( x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} \). Here, \( a = 3 \), \( b = 15 \), and \( c = -4200 \).

Substitute the values:

\[ x = \frac{-15 \pm \sqrt{15^2 - 4(3)(-4200)}}{2(3)} \]

Calculate the discriminant:

\[ x = \frac{-15 \pm \sqrt{225 + 50400}}{6} \]

\[ x = \frac{-15 \pm \sqrt{50625}}{6} \]

Calculate the square root:

\[ x = \frac{-15 \pm 225}{6} \]

Determine the possible values for \( x \):

  • Solution 1 (using +): \[ x = \frac{-15 + 225}{6} = \frac{210}{6} = 35 \]
  • Solution 2 (using -): \[ x = \frac{-15 - 225}{6} = \frac{-240}{6} = -40 \quad \text{(Invalid as the number of patients cannot be negative)} \]

Step 3: Final Answer

The number of patients admitted to hospital A is \( \boxed{35} \).

Was this answer helpful?
0


Questions Asked in CAT exam