Question

18. If a:b=5:6 and b:c=9:11, find the values of a, b and c.



19. If a:b=b:c, then, which of these is true

(a) a2 =bc

(b) b2 =ac

(c) c2 =ab

(d) None of these



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Answer 1

Answer:

19. a:b=b:c

Then,$\frac{a}{b}=\frac{b}{c}$

By cross multiplication,

b²=ac

18. one possible value of a, b and c is 45, 54 and 66 respectively.

explanation

a:b=5:6

Multiplying both by 9

a:b=45:54  .....1

b:c=9:11

Multiplying both by 6

b:c=54:66 .....2

from equation 1 and 2

a=45

b=54

c=66

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