Laura collects old foreign coins. She has 83 coins in total. She has 53 lira and drachma coins. She has 51 lira and peseta coins. How many lira coins does she have?

She has 21 lira coins.

Step-by-step explanation:

Given, Laura collects old foreign coins. She has 83 coins in total. She has 53 lira and drachma coins. She has 51 lira and peseta coins.

Let x = the number of lira coins.

y= the number of drachma coins.

z= the number of peseta coins.

Then, as per given, we have

x+y+z=83   (i)

x+y=53   (ii)

x+z=51   (iii)

From (ii) and (iii)

y=53-x

z=51-x

Put these values in (i) , we get

x+(53-x)+(51-x)=83

⇒ x+53-x+51-x=83

⇒ 104-x=83

⇒104-83=x

⇒x= 21

Hence, she has 21 lira coins.

step-by-step explanation:

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