Ali went to a shop to buy 50 kg of rice. He buys two varieties of rice which cost him Rs. 4.5 per kg and Rs.5 per kg. He appends a total of Rs. 240. What was the quality of cheaper rice bought by him?

22 kg

29 kg

20 kg

None of these

Let A be the amount of type of first rice and

B be the Amount of second type of rice

According to question: A + B = 50 Kg

Also

A x 4.5 + B x 5 = 240 Rs

Thus solving the above two equations

(50 – B) x 4.5 + 5B = 240

225 – 4.5 B + 5B = 240

0.5 B = 15

B = 15/ 0.5

B = 30 Kg

Thus A = 50 – 30 = 20 Kg