Ratio-algebraic method-tenth grade-25

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If 1/4 of A, 1/5 of B and 1/7 of C are equal, then find the ratio between A, B, C.

Solution: a/4 = b/5 = c/7 = x (say)

A = 4x

B = 5x

C = 7x

A : B : C = 4 : 5 : 7