Question

A:B=5:7 and B:C=6:11 then A:B:C=?

Answer 1

Given :

A : B = 5 : 7

B : C = 6 : 11

To Find :

A : B : C

Solution :

We can easily find  A : B : C whenever B in both ratios are same

B in 1st ratio = 7

B in 2nd ratio = 6

LCM of 7 , 6 is 42

$\sf \dfrac{A}{B}=\dfrac{5}{7}\\\\\to \sf \dfrac{A}{B}=\dfrac{5}{7}\times \dfrac{6}{6}\\\\\leadsto \sf \dfrac{A}{B}=\dfrac{30}{42}\ \; \bigstar$

$\sf \dfrac{B}{C}=\dfrac{6}{11}\\\\\to \sf \dfrac{B}{C}=\dfrac{6}{11}\times \dfrac{7}{7}\\\\\leadsto \sf \dfrac{B}{C}=\dfrac{42}{77}\ \; \bigstar$

A : B : C = 30 : 42 : 77

Answer 2

A:B=5:7,

B:C=6:11,

= a÷b =5÷7

and b÷c=6÷11

a=5÷7b and c=11:6b,

taking b =6×7=42, we get

a=5×6=30, c=11×7=77

hence , A:B:C=30:42:77