Question

a water tank contains 12 whole 1 upon 2 litre of water two fifth of it was consumed how much of it was left​

Answer 1

$\huge{\pink{\boxed{\purple{\boxed{\orange{\textsf{Solution}}}}}}}$

12½ is total water.

²/5 is the water used.

²/5 × 25/2

5

25/2 - 5

25/2 - 10/2

15/2

7.5

7.5 litres water remaining.

Answer 2

$\mathfrak{\large{\underline{\underline{Answer :-}}}}$

The water left is $7 \dfrac{1}{2}$ litres.

$\mathfrak{\large{\underline{\underline{Explanation :-}}}}$

Given :

Water tank consist of : $12 \dfrac{1}{2}$

$\dfrac{2}{5}$ consumed.

To find :

Water left

Solution :

Find the $\dfrac{2}{5}$th of $12 \dfrac{1}{2}$

$\tt{\implies} \: \dfrac{2}{5} \: of \: 12 \dfrac{1}{2}$

$\tt{\implies} \: \dfrac{2}{5} \times \dfrac{25}{2}$

Reduce 2 and 2. Reduce 5 and 25

$\tt{\implies} \: 5$

5 litres are consumed.

Subtract it from total water.

$\tt{\implies} \: 12 \dfrac{1}{2} - 5$

$\tt{\implies} \: \dfrac{25}{2} - \dfrac{5}{1}$

$\tt{\implies} \: \dfrac{25}{12} - \dfrac{5 \times 2}{1 \times 2}$

$\tt{\implies} \: \dfrac{25}{2} - \dfrac{10}{2}$

$\tt{\implies} \: \dfrac{15}{2}$

$\tt{\implies} \: 7 \dfrac{1}{2}$

$\therefore$ The water left is $7 \dfrac{1}{2}$ litres.