Question

one gas cylinder is used to cook food for a family of 8 people for 30 days . if 4 guests join the family how long will the cylinder last

Answer 1

1 cylinder for eight people lasts for 30 days.

So if we first we need to calculate the number of people one cylinder will last for: 
8 People * 30 days = 240 people / a cylinder

Now we calculate the number of days a cylinder last if it is used for 12 people:

1 cylinder for 12 people = 240/12 = 20 days

Therefore, the answer is: 20 days.

Answer 2

Answer:

The required number of days = 20 days.

Step-by-step explanation:

Number of peoples in the family = 8

One gas cylinder is used to cook food for 8 members for 30 days

So, number of people fed in 30 days = 8 × 30

                                                              = 240

Therefore, number of people whose food can be cooked by one gas cylinder = 240

Number of guest added into the family = 4

Now, number of members in the family = 12

240 peoples can eat by one gas cylinder for 30 days then 12 peoples can eat through :

$240\times \frac{1}{12}=20\:\:days$

Hence, The required number of days = 20 days.