Question

Dilliya has only ₹1 and ₹2 coins with her. If the total number of coins that she has is 25 and the amount of money with her is ₹40, then the number of ₹1 and ₹2 coins respectively are _____.

• A. 10 and 15
• B. 15 and 10
• C. 22 and 18
• D. 18 and 22

Answer 1

The correct option is A 10 and 15

Let the number of ₹1 coins be $x$ and that of ₹2 coins be $y$

Now, by given conditions $x+y=25---\left(i\right)$
and, $x\times 1+y\times 2=40$
$\Rightarrow x+2y=140---\left(ii\right)$
$\left(ii\right)-\left(i\right)⟹(x+2y)–(x+y)=40–25=15$
$\Rightarrow y=15$

Substituting this value of $y$ in $\left(i\right)$
$x+15=25$
$\Rightarrow x=10$

Thus, Dilliya has 100 ₹1 coins and 15 ₹2 coins.