Join 60,000+ competitive exam aspirants
or with email
Your Cart
Subtotal₹0
Total₹0
Examoogle • User • info@examoogle.com • EE-2024-8821
Chapter 1 of 12 • Page 1 of 248🔒 Protected PDF • Watermarked
Join 60,000+ competitive exam aspirants
A shopkeeper provides successive discounts of 7% and 2%, which are equivalent to a single discount of ____.
9%
9.14%
8%
8.86%
8.86%
Use the effective percentage change formula: a+b−(ab/100). Here, 7+2−(7×2/100)=9−0.14=8.86.
Two successive discounts of 7% and 2%.
SingleDiscount=(D1+D2−100D1×D2)%
Use the effective percentage change formula: a+b−(ab/100). Here, 7+2−(7×2/100)=9−0.14=8.86.
Many students mistakenly add the percentages to get 9% or multiply them incorrectly without subtracting from the sum.
Define the formula
To calculate the net discount resulting from two successive discounts of D1 and D2, use the formula:
TotalDiscount=(D1+D2−100D1×D2)%
Substitute given values
Plug the given discounts D1=7 and D2=2 into the formula:
TotalDiscount=(7+2−1007×2)%
Perform calculation
Calculate the sum and the product term: 7+2=9 and 10014=0.14. Then, subtract the result:
9−0.14=8.86%
D is correct because the equivalent single discount for successive discounts of 7% and 2% is calculated as 7 + 2 - (7 × 2 / 100) = 8.86%.
This concept is a specific application of the 'Net Percentage Change' formula, which is also used for calculating successive compound interest rates or consecutive population growth/decline.
Get instant step-by-step AI explanations, full shift Previous Year Papers (SSC GD, RRB, SSC JE), and regional rank analysis on the official Examoogle App.
Free Download • 100K+ Aspirants