Question

A drum contains 100 litre oil from which 3 cans of capacity 3 litres, 6 cans of capacity 5 litres, and 10 cans of 3 litres are to be filled with oil.
(i) How much oil will remain?
(ii) How many cans of capacity 2 litres can be filled from the remaining quantity of oil?

Answer 1

Hint: We have to find the total capacity of 3 cans of capacity 3 litres, 6 cans of capacity 5 litres, and 10 cans of 3 litres by multiplying the number of cans with their corresponding capacity. Then, we subtract the sum of these values from the total litres of oil in the drum to get the quantity of remaining oil. To find the number of 2 litres cans that can be filled with remaining oil, we have to divide the remaining oil by 2.

Complete step by step answer:
(i) We are given the total litres of oil in the drum $=100$ liters.
We are also given that 3 cans are of capacity 3 litres. Therefore, we can find the total amount of oil in 3 cans by multiplying 3 liters by 3.
$\Rightarrow $ Total capacity of 3 cans $=3\times 3=9\text{ litres}$
Similarly, we can find the capacity of 6 cans of capacity 5 litres.
$\Rightarrow $ Total capacity of 6 cans $=6\times 5=30\text{ litres}$
Similarly, we can find the capacity of 10 cans of 3 litres.
$\Rightarrow $ Total capacity of 10 cans $=10\times 3=30\text{ litres}$
Therefore, we can find the total amount of oil in 19 cans by adding the above values.
$\Rightarrow $ Total amount of oil in 19 cans $=9+30+30=69\text{ litres}$
69 litres have to be filled out of 100 litres. Therefore, we can find the remaining oil by subtracting 69 from 100.
$\Rightarrow $ Remaining oil $=100-69=31\text{ litres}$
Hence, the quantity of remaining oil is 31 litres.
(ii) To find the number of 2 litres cans that can be filled with 31 litres of oil, we have to divide 31 by 2.
 $\Rightarrow $ Number of 2 litres $=\dfrac{31}{2}=15.5\text{ }$
Therefore, 15 cans of capacity 2 litres can be filled by the remaining oil.

Note: Students must do the calculations carefully. They have a chance of making a mistake by dividing the number of cans by their corresponding capacity instead of multiplying them. In the last section of the solution, we have considered the integral part of 15.5. We will not consider the decimal part.