40 kg of rice lasts for 30 in a family of 8 persons. If 2 guests stay with the family, how many days will 40 kg of rice last?
THIS QUESTION IS FROM DIRECT AND INVERSE PROPRTION.
The following data can be represented using a table:
Let the number of days rice will last for 10 persons be x
If the number of persons increase, the number of days rice will last decreases. Hence this is a case of inverse variation.
Therefore
8 × 30 = 10 × x
10x= 240
x= 240/10 = 24 days
Let the number of days rice will last for 10 persons be x
If the number of persons increase, the number of days rice will last decreases. Hence this is a case of inverse variation.
Therefore
8 × 30 = 10 × x
10x= 240
x= 240/10 = 24 days