Question

A candle is 15cm long. If 35% of it burns away in an hour, how much of the candle is left after it has been lighted for 84 minutes?

Answer 1

= the lenght of candle is 15cm

= lenght of candle burnt in 1 hour is 35%

= that is ( 35 x 15 )  /100 cm

35 x 15 = 525 /100 = 5.25cm

= 5.25 cm of candle is burnt in one hour  (60 min)  

= lenght candle burnt in 84 min = 84 / 60 x 5.25  = 7.35 cm  

= left over lenght of candle = 08.00