The cost of 1 kg potato is 2 rupees. The cost of 1 kg onion is 25 paise and the cost of 1 kg ginger is 20 Rs. You have to buy 20 kg vegetables in 20 Rs only?
Answers
Answer:
The costs per kg are:
Tomato Rs. 1
Potato Rs. 5
Chilli Rs. 0.25
Over all, we need a cost of Rs. 1 per kg.
Looking at these numbers, we should first notice that the quantity of tomatoes doesn't change the average price as their cost is exactly same as the desired cost.
The weighted average cost of Potatoes and Chillies should be equal to 1 rupee.
{math}\frac{5p+0.25c}{p+c}=1{\math}
From this we get [math] \frac{p}{c}=\frac{3}{16}[\math]
One obvious solution is to take 3 kg of potato (15 rupees), 16 kg of chilli (4 rupees) and 1 kg of tomato.
Faster way
Compared to the desired average(1 ₹), the cost of potato is 4 rupees higher and cost of chilli is 0.75 lower. They are in the ratio 4:0.75= 16:3.
The way to bring them upto average is by taking them in the ratio 3:16.
Step-by-step explanation: