Question

Maitri and Aabhas do a work in 12 hours.

Answer 1

Answer:

See below ~

Step-by-step explanation:

Given

• Maitri and Aabhas do a work in 12 hours
• Aabhas and Kavya do the work in 15 hours
• Kavya and Maitri do the work in 20 hours

Solving

• Take Maitri, Aabhas, and Kavya to be x, y, z respectively
• x + y = 12 (1)
• y + z = 15 (2)
• x + z = 20 (3)

Take Equation 1 and rewrite it so that it is equal to x.

• x = 12 - y

Take Equation 2 and rewrite it so that it is equal to z.

• z = 15 - y

Now, substitute these values in Equation 3.

• x + z = 20
• 12 - y + 15 - y = 20
• -2y + 27 = 20
• 2y = 7
• y = 7/2 = 3.5 hours [Aabhas]

Substitute the value of y in Equation 1.

• x + 3.5 = 12
• x = 8.5 hours [Maitri]

Substitute the value of y in Equation 2.

• 3.5 + z = 15
• z = 11.5 hours [Kavya]

Add the values of x, y, and z together.

• x + y + z
• 8.5 + 3.5 + 11.5
• 12 + 11.5
• 23.5 hours [together]