Question

One quality of wheat at rs. 9.30 per kg is mixed with another quality at certain rate in the ratio 8 : 7 .If the mixture so formed be worth rs. 10 per kg,what is the rate per kg of the second quality of wheat ?

Answer 1

Ratio = 8 : 7

Find the total weight of the mixture:

Total weight = 8 + 7 = 15 kg

Define x:

Let x be the cost of the other wheat

Find the total cost of the 15kg

Total cost = 8(9.30) + 7x = 74.4 + 7x

Solve x:

The mixture is worth Rs 10 per kg

74.4 + 7x = 15(10)

74.4 + 7x = 150

7x = 150 - 74.4

7x = 75.6

x = Rs 10.80

Answer: The other quantity of wheat is Rs 10.80 per kg.

Answer 2

Lets consider,

price of wheat = a = 9.3 rs/kg

price of unknown grain = b = ?

According to given condition,

Ratio = 8/7

Total weight = 8+7=15kg

8a + 7b = 10(15)

8 × 9.3 +7b =150

7b = 150 - 74.4

7b = 75.6

b = 75.6/7

b = 10.8 rs/kg

Price of unknown grain is 10.80 Rs/kg.

Best Luck...