Question

A box contains 4 bags of sugar. The total mass of all the 4 bags is 7kg. What is the mass of each bag in grams?
(a) 1.75gms
(b) 17.50gms
 (c) 175gms
(d) 1750gms

Answer 1

Hint: We will first assume the mass of each bag to be some variable say x. Then, we are given that the mass of 4 bags is 7kg. So, we have an equation as $4x=7$ . On solving this answer, we will get an answer in kg. So, we will convert it into grams using the rule $1kg=1000gms$ . Thus, we will then get the answer.

Complete step-by-step answer:
Here, we will assume that the weight of each bag of sugar is some random variable x. Now, we are given that the total mass of 4 bags is equal to 7kg. So, we can write in mathematical form as
$x+x+x+x=7kg$
$4x=7$
On dividing it with 4 on both sides, we will get
$x=\dfrac{7}{4}=1.75kg$
Now, we will convert it into grams as our options given in the question are in grams units. So, we will use the rule of conversion as $1kg=1000gms$ .
On using unitary method, we will get as
$\begin{align}
  & 1kg=1000gms \\
 & 1.75kg=? \\
\end{align}$
On solving, we get
$=100\times 1.75gms$
$=1750gms$
 Thus, the mass of each bag is 1750gms.
Hence, option (d) is the correct answer.

Note: Another way to solve this problem is by option method. We can take each option and add it 4 times as there are4 bags of sugar. Then on getting answers in grams we will convert it into kilogram units using the rule $1kg=1000gms$ . Then we will see whether it is equal to 7kg or not.
So, taking option (a): 1.75gms. On adding 4 times, we will get $1.75+1.75+1.75+1.75=7gms$ . Now, converting this into kg, we will get as
$\begin{align}
  & 1kg=1000gms \\
 & ?=7gms \\
\end{align}$
On solving, we will get an answer as $\dfrac{7\times 1}{1000}=0.007kg$ . So 0.007 is not the same as 7kg. Thus, this is not the correct answer. By doing this way we will have the same answer i.e. option (d).