Ruby bought a watermelon weighing 5 kg 300 g. Out of which she gave 2 kg 680 g to her neighbour. What is the weight of the watermelon left with Ruby?

Options

A. 2.45 kg
B. 3.45 kg
C. 4.45 kg
D. 5.45 kg

Answer

To solve the problem step by step, we will follow these calculations:

### Step 1: Convert the weight of the watermelon Ruby bought into grams.
- Ruby bought a watermelon weighing 5 kg 300 g.
- We know that 1 kg = 1000 grams.
- Therefore, 5 kg = 5 × 1000 g = 5000 g.
- Now, we add the additional 300 g to this:
\[ 5000 \text{ g} + 300 \text{ g} = 5300 \text{ g} \]

### Step 2: Convert the weight of the watermelon given to the neighbor into grams.
- Ruby gave away 2 kg 680 g to her neighbor.
- Again, using the conversion of kg to grams:
- 2 kg = 2 × 1000 g = 2000 g.
- Now, we add the additional 680 g to this:
\[ 2000 \text{ g} + 680 \text{ g} = 2680 \text{ g} \]

### Step 3: Calculate the weight of the watermelon left with Ruby.
- Now, we need to find out how much watermelon Ruby has left after giving some to her neighbor:
\[ \text{Weight left} = \text{Weight bought} - \text{Weight given away} \]
- Substituting the values we calculated:
\[ 5300 \text{ g} - 2680 \text{ g} = 2620 \text{ g} \]

### Step 4: Convert the remaining weight back into kg and g.
- To express 2620 g in kg and g:
- We know that 1 kg = 1000 g, so we divide 2620 by 1000:
- The whole number part is 2 (which represents kg).
- The remainder is 620 (which represents grams).
- Therefore, 2620 g = 2 kg 620 g.

### Final Answer:
The weight of the watermelon left with Ruby is **2 kg 620 g**.

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