Question

Ram went to a shop to buy 50 kg of rice. he buys two kinds of rice which cost him rs. 4.50 per kg and rs. 5.00 per kg. he spends a total of rs. 240. what was the quantity of rice bought which cost him rs. 4.50 per kg.

Answer 1

Let A be the amount of type of first rice
and
B be the Amount of second type of rice

Thus according to question

A + B = 50 Kg
Also
A * 4.5 + B * 5 = 240 Rs
Thus solving the above two equations
(50 - B) * 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

Answer 2

Step-by-step explanation:

let Ram will buy x kg rice of first kind

and y kg of second type

so ,

1st case

x+y = 50kg...............(1)

x = 50-y..................(2)

Rate of x kg rice = ₹5

so cost of first quality rice = 5x

similarly

rate of y kg rice = 4.50

cost = 4.50 y

second case

5x+4.50y= 240.... ..........(3)

putting value of x= 50-y from eq.(2) to eq.(3)

5x+4.50y= 240

5(50-y)+4.50y= 240

250-5y+4.5y= 240

-0.5y=240-250

-0.5y= -10

0.5y= 10 {multiplying by(-1) in both sides}

y= 10/0.5

y=100/5

y= 20

so he buys 20kg rice with the rate of ₹4.5

20 kg is your answer

now if you want to how much will he buy with the rate of 5

then

x= 50-y

x= 50-20

x = 30

he will buy 30kg with the rate of ₹5