Question

2. Rahul sold a watch to Sohan at a gain of 10% and Sohan sold it to Mohan at a loss of
10%. If Mohan paid 990 for it, find the price paid by Rahul.
​

Answer 1

✬ Cost = Rs 1000 ✬

Step-by-step explanation:

Given:

• Rahul sold a watch to Sohan at gain of 10%.
• Sohan sold that watch to Mohan at loss of 10%.
• Mohan paid Rs 990 for the watch.

To Find:

• Find the price paid by Rahul ?

Solution: Let the cost price of watch be Rs x.

As we know that

★ S.P = C.P × ( 100 + gain%/100 ) ★

➟ S.P = x × ( 100 + 10/100 )

➟ x × 110/100

➟ 110x/100

➟ 11x/10

A/q

• Rahul sold watch at 11x/10. [ S.P for him ]

• Sohan bought watch at 11x/10. [ C.P for him ]

• Sohan sold this watch at loss of 10%.

★ S.P = C.P × ( 100 – Loss%/100 ) ★

➟ S.P = 11x/10 × ( 100 – 10/100 )

➟ 11x/10 × ( 90/100 )

➟ 11x/10 × 9/10

➟ 99x/100

A/q

• Sohan sold watch at 99x/100. [ S.P for him ]

• Mohan bought watch for 99x/100. [ C.P for him ]

• Mohan paid Rs 990.

$\implies{\rm }$ 990 = 99x/100

$\implies{\rm }$ 990 × 100 = 99x

$\implies{\rm }$ 990 × 100/99 = x

$\implies{\rm }$ 10 × 100 = x

$\implies{\rm }$ Rs 1000 = x

Hence, the price paid by Rahul is Rs 1000.

Answer 2

Answer:

✠ Given :-

• Rahul sold a watch to Sohan at a gain of 10% and Sohan sold it to Mohan at a loss of 10%. Mohan paid Rs 990.

✠ To Find :-

• How much price paid by Rahul.

✠ Formula Used :-

❖ SP = CP × (1 + Gain/100) ❖

✦ SP = CP × (1 - Loss/100) ✦

✠ Solution :-

Let, the Rahul paid be Rs x

First,

➣ SP of Rahul to Sohan at gain 10%,

According to the question by using the formula we get,

⇒ x × (1 + 10/100)

⇒ (x × 11/10)

⇒ 11x/10

Hence, CP of Sohan = Rs 11x/10

Now,

➣ SP of Sohan to Mohan at loss 10%,

According to the question by using the formula we get,

↦ 11x/100 × (1 - 10/100)

↦ 11x/100 × 9/10

↦ 9 × 11x/100

Now, given in the question that,

Mohan paid = Rs 990

According to the question,

↬ 9 × 11x/100 = 990

↬ x = 990 × 100/9 × 11

↬ x = 99000/99

➠ x = Rs 1000

∴ Total price paid by Rahul is Rs 1000 .