Question

A shirt costs Rs. 350. If the cost is increased by 10%, then the new cost will be:
1. Rs. 360
2. Rs. 270
3. Rs. 365
4. Rs. 385

Answer 1

Correct Answer - Option 4 : Rs. 385

Given:

Cost of shirt = Rs. 350

Percentage increase in cost = 10%

Concept:

Percentage Increase = (100 + x)%

Solution:

Let the increased cost of shirt be Rs. x.

Cost of shirt = Rs. 350

Percentage increase in cost = 10%

⇒ New cost = 110% of Previous cost

⇒ x = 110/100 × 350

⇒ x = 385

∴ The new cost of shirt is Rs. 385.

Short Trick/Topper's Approach:

Percentage increase in cost = 10%

⇒ New cost : Previous cost = 11 : 10      [10% = 1/10]

Previous cost of shirt = Rs. 350

⇒ 1 unit = 350/10 = 35

⇒ New cost of shirt = Rs. 11 × 35

⇒ New cost of shirt = Rs. 385

∴ The new cost of shirt is Rs. 385.