Question

Sunita gained 7 kg 500 g weight. What was her weight earlier if she weighs 50 kg 200 g now?

Answer 1

Hint:We have two different weights and each weight we need to convert into kilograms divided by 1000 and add it to the existence kilogram and her weight is given by taking the difference between the weight she weighs now and the weight she gained. Hence, in this way we get the desired value in the kilogram. We can also write in the terms of kilogram as well as gram.

Complete step by step answer:
We are given that Sunita has gained 7 kg and 500 g and she weighs 50 kg 200 g. Then earlier her weight is nothing but the difference between the Current weight and gained weight.
Weight which she already gained which is also referred to as gained weight \[=7\,kg\,500\,g\].

So, first of all we need to convert this gained weight in grams into kilograms. As we know that \[1g=0.0001\,kg\]therefore\[500g=0.5kg\] then add in to the existence kilogram that means \[\text{Gained}\,\text{weight}=7\,kg+\,0.5\,kg=7.5\,kg---(1)\]
She weights now which is also referred to as current weight \[=50\,kg\,200\,g\]

So, first of all we need to convert this gained weight in grams into kilograms. As we know that \[1g=0.0001\,kg\] therefore \[200g=0.2kg\] then add in to the existence kilogram that means \[\text{Current}\,\text{weight}=50kg+\,0.2\,kg=50.2kg---(2)\].

To find the earlier weight we need to take the difference between Current weight and Gained weight. That means,
\[\text{Earlier}\,\text{weight}=\text{Current}\,\text{weight}-\text{Gained}\,\text{weight}---(3)\]
By substituting the value of equation (1) and equation (2) on equation (3).
\[\text{Earlier}\,\text{weight}=50.2\,\text{kg}-7.5\,\text{kg}\]
Therefore, after simplifying this we get:
\[\text{Earlier}\,\text{weight}=42.7\,\text{kg}\]
We can also write in the form of \[\text{Earlier}\,\text{weight}=42\,\text{kg}\,\text{700}\,\text{g}\]

Therefore, Earlier weight is \[42\,\text{kg}\,\text{700}\,\text{g}\].

Note: Always remember that when we are converting kilogram into gram then we have to multiply by 1000 and when we convert gram into kilogram then we have to divide by 1000. This is derived from the fact that \[1\,kg=1000\,g\]. Most of the students make mistakes. They directly subtract kilogram and gram then end up with wrong answers. But you have to note that while subtracting units should be the same. Another mistake can happen to a student by seeing the question directly subtract \[\text{lower number}-\text{bigger number}\]. And end up with a negative answer. But you have to always remember that weight cannot be negative. Hence you have to subtract \[\text{bigger number}-\text{lower number}\]. So, these things you have to keep in mind while solving such types of problems.