Question

Q9 The efficiencies of X and Y are
in the ratio 7:9. If Y can do a
piece of work in 28 hours, then
X can do it in:​

Answer 1

Step-by-step explanation:

Sum of the ratio =7+9

=16

X can do =7/16×28= 12.25

Y can do =9/16×28=15.75

May it help you

Answer 2

X can do the work in 36 hours.

Let's assume that the efficiency of X is 7k and the efficiency of Y is 9k.

Therefore, the ratio of the efficiency of X and Y is 7:9.

We know that,

Efficiency = Work done / Time taken

Let's assume that the total work is 1 unit.

Then, Y can do the work in 28 hours with an efficiency of 9k.

Therefore,

1 = 9k × 28

k = 1/252

Now we can find the efficiency of X:

Efficiency of X = 7k

Efficiency of X = 7 × (1/252)

Efficiency of X = 1/36

Therefore, X can do the work in:

Time taken by X = Work done / Efficiency of X

Time taken by X = 1 / (1/36)

Time taken by X = 36 hours

Hence, X can do the work in 36 hours.

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