Question

Given, $800{\text{ }}kg$ of mortar consists of $55\%$ sand, $33\%$ cement and rest lime. What is the mass of lime in mortar?

Answer 1

For the given problem, first we need to find the mass of sand and cement using the given details of percentage composition and total weight of mortar. The mass of lime in mortar can be calculated by subtracting the total mass of sand and cement calculated earlier from the total mass of mortar given.

Complete answer:
As given, Mass of mortar is $800kg$
Mass of sand in mortar is $55\% \;of\;800kg$
Mass of sand in mortar $= \left( {10055 \times 800} \right)kg = 440kg$
Mass of cement in mortar is $33\% \;of\;800kg$
Mass of cement in mortar $= \left( {10033 \times 800} \right)kg = 264kg$
Therefore, mass of lime in mortar will be
$=800- (400+264) kg$
$96kg$
Hence, the mass of lime in mortar is $96kg$.

Note:
An alternative method of calculating the same is given as following -
Percentage of sand in mortar is $55\%$
Percentage of cement in mortar is $33\%$
So, the percentage of lime in mortar is $100-55-33\; = 100-88\; = 12\%$
∴ Weight of mortar is $\;800{\text{ }}kg$
∴ Mass of lime in mortar is $12\% {\text{ }}of{\text{ }}800{\text{ }}kg\; = 12/100\; \times 800\; = 12 \times 8\; = 96{\text{ }}kg$
Hence, the weight of lime in mortar is $96{\text{ }}kg$.