For a 4th of July parade, every 4th lamp post has red and white balloons and every 7th lamp post has blue and white balloons. When will a lamp post have red, white, and blue balloons?

A11th lamp post
B14th lamp post
C28th lamp post
D36th lamp post

Verified Answer :

Answer is C 28th lamp post

Answer:  The correct option is

(C) 28th lamp post.

Step-by-step explanation:  Given that for a 4th July parade, every 4th lamp post has red and white balloons and every 7th lamp post has blue and white balloons.

We are to select the number of lamp post that will have red, white and blue balloons.

Since every 4th lamp post has red and white balloons and every 7th lamp post has blue and white balloons, so

the number of lamp post that will have all red, white and blue balloons will be the LCM of 4 and 7.

That is,

LCM (4, 7) = 4 × 7 = 28.

Thus, the 28th lamp post will have red, white and blue balloons.

Option (C) is CORRECT.