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The sum of three numbers, namely, A, B and C is 156. The numbers A and B are in the ratio of 2:5, while B and C are in the ratio of 1:9. Find number B?

Solution

✅ Correct Option: 2

A and B are in the ratio 2:5.

A=2kA = 2k and B=5kB = 5k for some value kk.

B and C are in the ratio 1:9.

B=mB = m and C=9mC = 9m for some value mm.


Since both expressions represent B:

5k=m5k = m

C=9mC = 9m

C=9(5k)C = 9(5k)

C=45kC = 45k


All three numbers in terms of kk:

A=2kA = 2k

B=5kB = 5k

C=45kC = 45k


The sum equals 156:

A+B+C=156A + B + C = 156

2k+5k+45k=1562k + 5k + 45k = 156

52k=15652k = 156

k=3k = 3


B=5kB = 5k

B=5×3B = 5 \times 3

B=15B = 15

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