Riddle

Question

I need help solving a riddle - A tourist an Eiffel Tower snow dome and an Arc de Triomphe postcard. They both cost 110 francs and theanow dome costs 100 francs more than the postcard. Thank you ?

Deadrat · Accepted Answer

Let's start by phrasing the riddle properly:

"A tourist wants to buy an Eiffel Tower snow dome and an Arc de Triomphe postcard. Together they cost 110 francs_*, and the snow dome costs 100 francs more than the postcard_**." Presumably the riddle isn't why this transaction isn't being made in euros.

Let d = cost of the dome.
Let p = cost of the postcard

(*) d+p = 110
(**) d = p+100

Subtract (**) from (*) to get

(d+p)-d = 110 - (p+100) or
p = 10 - p.

Add p to each side to get

2p = 10. Divide each side by 2 to get p = 5.

Substitute 5 for p in (**) to get d = 5+100 = 105.

So the dome costs 105 francs, and the postcard costs 5 francs. Sure enough together they cost 110 francs (105+5), and the dome costs 100 francs more than the postcard.

Riddle

Top answer

Get the Weekly English Kit 📬