Question

How many kgs of wheat costing Rs.8 per kg must be mixed with 36 kg of rice costing Rs.5.40 per kg so that 20% gain may be obtained by selling the mixture at Rs.7.20 per kg?

• A. 10.08 kg
• B. 8.6 kg
• C. 9.2 kg
• D. 10.8 kg

Answer 1

Answer: (D)

10.8 kg

Let $x$ kgs of wheat be required to be mixed with $36$ kg of rice

Cost of the wheat $=8x$

Cost of rice $=36\times 5.40=194.40$

Total cost $=8x+194.40$

Selling price expected after $20\%$ gain $=(1+\frac{20}{100})\times (8x+194.40)=1.2\times (8x+194.40)$

Actual selling price $=Rs\left(7.20\right)\times (x+36)kg$

$7.2(x+36)=1.2(8x+194.4)$

$7.2x+259.2=9.6x+233.28$

$25.92=2.4x$

$x=10.8kg.$