Question

Un groupe d'amis décide d'organiser une sortie au restaurant. Ils prennent contact avec un restaurateur qui leur propose une formule à 20 € par convive. Le jour de la sortie, cinq personnes ne peuvent venir. Les participants doivent alors payer 22 € par personne. Combien de personnes étaient initialement prévues ?

Answer 1

55

Explanation:

Assuming that, initially, there were x people at the time of planning.

As given that, initially, the cost for 1 person = € 20

So, Total cost = € 20x ...(i)

As on the day of the outing, five people cannot come, so the number of people on the outing = x-5.

Now, due to the lesser number of people, i.e (x-5), the cost for 1 person = € 22.

Total cost = € 22(x-5) ...(ii)

As total cost remains the same, so equation the total cost from equations (i) and (ii), we have

`20x= 22(x-5) \\\\\Rightarrow 20x=22x-22* 5 \\\\\Rightarrow 22x-20x= 110 \\\\\Rightarrow 2x=110 \\\\\Rightarrow x=110/2=55.`

Hence, at the time of planning, there were 55 people.