Question

Are 3, 5, 15, 9 in proportion? If we change their order, can we think of proportional pairs? Write as many proportionality statements as you can for the given example.?

Answer 1

Hi ,

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If a , b , c , d are in proportion then

ad = bc

product of extremes = product of means

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1 ) if a = 3 , b = 5 ,

c = 15 , d = 9

ad = 3 × 9 = 27

bc = 5 × 15 = 75

ad ≠ bc

3 , 5 , 15 , 9 are not in proportion.

2 ) Let a = 3 , b = 5 ,

c = 9 , d = 15

ad = 3 × 15 = 45

bc = 5 × 9 = 45

Therefore ,

ad = bc

3 , 5 , 9 , 15 are in proportion

3 ) 3 , 9 , 5 , 15

4 ) 15 , 5 , 9 , 3

5 ) 15 , 9 , 5 , 3

are in proportion.

I hope this helps you.

: )