Question

Six boys of equal working capacity can paint 9 doors in a day. How many boys are required to paint 15 doors in a day?

Answer 1

Answer:

6 boys =9 doors

1 boys = 9÷6

1 boys = 1.5

15 door = 15×1.5

=22.5

Answer 2

Given:

✰ Six boys of equal working capacity can paint 9 doors in a day.

To find:

✠ How many boys are required to paint 15 doors in a day?

Solution:

Let's understand the concept! We know that Six boys of equal working capacity can paint 9 doors in a day and we need to find the number of boys required to paint 15 doors in a day. When the number of doors increase, the boys required to paint the door will also increase, Thus it is a direct variation.

• The two quantities are said to be have direct variation, if increase in one quantity causes an increase in other quantity, as in this case.

Let the number of boys required to paint 15 doors be x.

It is a case of direct variation

✭ x₁/y₁ = x₂/y₂✭

Where,

• x₁ = 6
• y₁ = 9
• x₂ = x
• y₂ = 15

Putting the values,

➛ 6/9 = x/15

➛ x = 6/9 × 15

➛ x = 2/3 × 15

➛ x = 2 × 5

➛ x = 10

∴ 10 boys required to paint 15 doors.

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