Percentage - Study Mode

[#166] If x% of y is the same as $$frac{4}{5}$$ of 80, then the value of xy is :
Correct Answer

(D) None of these

Explanation

Solution: $$frac{x}{100}$$ × y = $$frac{4}{5}$$ × 80 ⇒ xy = 64 × 100 ⇒ xy = 6400

[#167] The contents of a certain box consist of 14 apples and 23 oranges. How many oranges must be removed from the box so that 70% of the pieces of fruit in the box will be apples ?
Correct Answer

(C) 17

Explanation

Solution: Total number of fruits = (14 + 23) = 37 Let x oranges be removed. Then, 70% of (37 - x) = 14 ⇒ 7 (37 - x) = 140 ⇒ 37 - x = 20 ⇒ x = 17

[#168] If house tax is paid before the due date, one gets a reduction of 12% on the amount of the bill. By paying the tax before the due date, a person got a reduction of Rs. 2,100. The amount (in Rs.) of house tax was:
Correct Answer

(B) 17,500

Explanation

Solution: [x08egin{array}{*{20}{c}}
{D = }&{12\% }& o &{2100} \
{}&{1\% }& o &{175} \
{}&{100\% }& o &{17500}
end{array}]

[#169] If the price of eraser is reduced by 25%. A person can buy 2 more erasers for a rupee. How many erasers are available for a rupee after reduction?
Correct Answer

(A) 8

Explanation

Solution: According to the question, 1 unit → 2 3 units → 2 × 3 = 6 ereaser 4 units → 2 × 4 = 8 ereaser

[#170] $$frac{{11}}{5}$$ of a number A is 22% of a number B. The number B is equal to 2.5% of a third number C. If the value of C is 5500, then the sum of 80% of A and 40% of B is:
Correct Answer

(D) 66

Explanation

Solution: $$eqalign{
& frac{{11}}{5}A = frac{{22}}{{100}}B cr
& frac{A}{B} = frac{1}{{10}} cr
& B = frac{{25}}{{1000}}C cr
& frac{B}{C} = frac{1}{{40}} cr} $$ [x08egin{array}{*{20}{c}}
{A,,,:,,,B,,,:,,,C} \
{,1,,,,,,,,,,10,,,,,,,,,,10} \
{,1,,,,,,,,,,,,1,,,,,,,,,,,40} \
{overline {,,1,,:,,40,,:,,400,} }
end{array}] $$eqalign{
& 400 o 5500 cr
& 400 o frac{{55}}{4} cr
& A o frac{{55}}{4} cr
& B o frac{{550}}{4} cr
& { ext{According to the question,}} cr
& left( {frac{{80}}{{100}} imes frac{{55}}{4}}
ight) + left( {frac{{40}}{{100}} imes frac{{550}}{4}}
ight) cr
& = 11 + 55 cr
& = 66 cr} $$