Question

1) A and B working together can finish a piece of work in 9 days while B alone can do it in 12 days how much time will A alone take to finish it

2) A toy is sold for 7000 at a loss of 10% what it is CP?

solve both with process​

Answer 1

1 )

Given :-

Work together done by A,B is 9 days

Work done by B alone is 12 days

To find :-

Work done By A alone is ?

Lets do !

Let work done by A is x

One day work of A, B is 1 /9

One day work of B is 1 /12

One day work by A is 1/x

So,

One day work of A ,B = One day work of A + One day Work Of B

$\sf\dfrac{1}{9}$ = $\sf\dfrac{1}{12}$ + $\sf\dfrac{1}{x}$

Tranpose 1/12 to RHS

$\sf\dfrac{1}{9}$ - $\sf\dfrac{1}{12}$ = $\sf\dfrac{1}{x}$

Take LCM to denominators in LHS

$\sf\dfrac{4 - 3 }{36}$ = $\sf\dfrac{1}{x}$

$\sf\dfrac{1}{36}$ = $\sf\dfrac{1}{x}$

One day work of A is 1/36

Time taken to finish the work by A alone is 36 days

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Given :-

• 2) SP = 7000 Rs
• Loss = 10 %

To find :-

• CP = ?

Formula Implemented:-

CP = 100/ 100-L% × Sp

Plugging values !

CP = $\sf\dfrac{100}{100-10}$ 7000

CP = $\sf\dfrac{100}{90}$ 7000

CP = $\sf\dfrac{10}{9}$ 7000

CP = $\sf\dfrac{70000}{9}$

CP = 7,777.7 Rs

CP of item is 7777.7 Rs

__________________

Know more about Profit & Loss

When C.P > SP We get loss

SP > CP We get profit

SP - CP = profit

CP - SP = loss

Profit % = $\sf\dfrac{Profit}{CP}$ 100

Loss % = $\sf\dfrac{Loss}{CP}$ 100