p kg of potatoes are bought for Rs 70. Cost of 1 kg of potatoes (in Rs) is _________.
p kg of potatoes are bought for Rs 70. Cost of 1 kg of potatoes (in Rs) is 70/p.
Step 1: We are told that p kilograms of potatoes cost Rs 70.
Step 2: To find the cost of 1 kilogram, use the unitary method:
Cost of 1 kg = (Total cost) ÷ (Total kilograms)
Step 3: Write the known values:
Total cost = (70) (rupees)
Total kilograms = (p) (kg)
Step 4: Substitute into the formula in small steps:
( ext{Cost of 1 kg} = dfrac{ ext{Total cost}}{ ext{Total kilograms}})
( ext{Cost of 1 kg} = dfrac{70}{p})
So, the cost of 1 kg of potatoes is (dfrac{70}{p}) rupees.
Quick check (example): If (p = 10) kg, then cost of 1 kg = (70 div 10 = 7) rupees. This matches our formula.
Note: (p) must be greater than (0); you can’t buy (0) or negative kilograms.