If 7 kg of onions cost `₹` 140, how much must we pay for 12 kg of onions ?

Explanation

Let the cost of 12 kg of onions be `₹` x.
The weight of onion and its cost are in direct proportion.
`therefore 7/140=12/x`
`therefore 7x=140xx12`
`therefore (7x)/7=(140xx12)/7`
`therefore`x=240
We pay `₹` 240 for 12 kg of onions.