Page 17 - SPARK OF MATH book 6
P. 17
(1-7) Problem Solving.
A hall has two towers with rotating floodlights.
Floodlight A takes 30 seconds to complete a revolution
while Floodlight B takes 25 seconds. At a certain
instance, both floodlights shine at a point C.
When will both floodlights shine again
simultaneously on the point C?
Sara has 3 types of ribbon of lengths 84cm, 140cm
and 308cm. She wishes to cut the ribbons into pieces
of the same length for making butterfly knots.
a) What is the greatest possible length that she can cut
for each piece, if no ribbon is to be left unused?
b) How many pieces of butterfly knots of equal
lengths will she get?
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