Question

Minu sells a watch at a profit of 10% and invest the proceeds to buy clock which she sells at a profit of 20%. If he makes a net profit of ₹700 then what is a cost of watch?​

Answer 1

Answer:

Let the cost of the watch = Rs. x.

Then, cost of the clock = Rs. (390−x)

Given, 10% of x+15% of (390−x)=51.50

⇒

10

x

+

100

15×(390−x)

=51.50

⇒10x+5850−15x=5150

⇒5x=700

⇒x=140

∴ Cost of clock = Rs. (390−140)= Rs. 250

∴ Required difference = Rs. 250−Rs. 140=Rs. 110.

Answer 2

Given:

Minu sells a watch at a profit of 10%

She invest the proceeds to buy clock which she sells at a profit of 20%.

She makes a net profit of ₹700

To find :

The cost of a watch.

Solution:

Step 1 of 2:

Let the cost of a clock be 'x'

She sells the clock at a profit of 20%. She makes a net profit of ₹700

x + 20% of x = x + 700

x + 20 × $\frac{x}{100}$ = x + 700

x + $\frac{x}{5}$ = x + 700

$\frac{5x+x}{5}$= x + 700

6x = 5( x + 700 )

6x = 5x + 3500

6x - 5x = 3500

x = 3500

The cost of the clock is ₹3500

Step 2 of 2:

Minu sells a watch at a profit of 10% and invest the proceeds to buy clock.

Let the cost of watch is 'y'

y + 10% of y = 3500

y + 10 × $\frac{y}{100}$ = 3500

y + $\frac{y}{10}$ = 3500

$\frac{10y+y}{10}$ = 3500

11y = 10(3500)

11y = 35000

y = $\frac{35000}{11}$

y = 3181.81

The cost of watch is ₹3182

Final answer:

The cost of a watch is ₹3182