Question

6)p is able to do a piece of work in 15 days and q can do the same work in 20 days. If they can work together for 4 days, what is the fraction of work left

Answer 1

Here's your answer!!

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P can do a piece of work in 15 days

One day work of P,

$= > \frac{1}{15}$

Q can do piece of work in 20 days


One day work of Q,

$= > \frac{1}{20}$

(P+Q)'s one day work

$= > \frac{1}{15} + \frac{1}{20} \\ = > \frac{4 + 3}{60}$

$= > \frac{7}{60}$

They worked for 4 days so fraction of work completed =

$= > \frac{7}{60} \times 4 \\ = > \frac{7}{15}$

Fraction of work left =

$= > 1 - \frac{7}{15} \\ = > \frac{15 - 7}{15} \\ = > \frac{8}{15}$

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Hope it helps you!! :)

Answer 2

Answer:

8/15

Step-by-step explanation:

Amount of work P can do in 1 day = 1/15

Amount of work Q can do in 1 day = 1/20

Amount of work P and Q can do in 1 day = 1/15 + 1/20 = 7/60

Amount of work P and Q can together do in 4 days = 4 × (7/60) = 7/15

Fraction of work left = 1 – 7/15= 8/15