solve the problem

Question

mangoes cost X dollar for the first 1.5 kg. All amount in addition to first 1.5 kg cost 50 dollar per kg. How much does it cost to buy total 5 kg mangoes?

 

Answer 1

the question tells us that mangoes cost $50 per kilogram (kg). If we want to know how much 5 kg of mangoes costs, we could multiply the number of kg x cost/kg = 5 kg x $50/kg = $250
But in the beginning of the question, it says there is a special price for the first 1.5 kg that is bought and it is called x dollars.
 
Because we already know the cost of the first 1.5 kg, we need to subtract that amount from the total kg so that we calculate the cost of only the additional kg.
 
So 5 - 1.5 = 3.5 kg
 
The cost of 3.5 kg is 3.5 x $50/kg = $175
 
So can you write what the total cost is? (hint: don't forget the initial cost X)

Answer 2

Rifat,

 

If the price of mangoes is $50/kg then 1½ kg will cost 1½ x $50 = $75

 

You can do the rest of this is your head, the next  1½ will cost and additional $75 bring your total to: $150 for 3 kg of mangoes.  5 kg - 3 kg means you still have 2 kg left to purchase at $50/kg so the cost of the next 2 kg is $100

 

Your total cost for 5 kg is then $150 + 100 = $250

 

You can of course solve this in one step by paying attention to the statement that you need to purchase 5 kg of mangoes for $50/kg.  Since there is no discount or special price offered for the 1st 1.5 kg, you answer is simply:

 

Total cost = 5kg x $50/kg = $250