Percentage - Study Mode

[#411] A bakery opened with its daily supply of 40 dozen rolls. Half of the rolls were sold by noon and 60% of the remaining rolls were sold between noon and closing time. How many dozen rolls were left unsold ?
Correct Answer

(B) 8

Explanation

Solution: Number of rolls sold by noon = $$frac{1}{2}$$ of 40 dozen = 20 dozen Number of rolls sold between noon and closing time : = 60% of 20 dozen = $$left( {frac{{60}}{{100}} imes 20}
ight)$$ xa0 dozen = 12 dozen Number of rolls left unsold : = [40 - (20 + 12)] dozen = 8 dozen

[#412] Find the missing value : 35568 ÷ ? of 650 = 456
Correct Answer

(A) 12

Explanation

Solution: Let 35568 ÷ x% of 650 = 456 Then, $$eqalign{
& Rightarrow 35568 div left( {frac{x}{{100}} imes 650}
ight) = 456 cr
& Rightarrow frac{{13x}}{2} imes 456 = 35568 cr
& Rightarrow 2964x = 35568 cr
& Rightarrow x = frac{{35568}}{{2964}} cr
& Rightarrow x = 12 cr} $$

[#413] The value of which of the following fractions is less than twenty percent ?
Correct Answer

$$frac{5}{61}$$

Explanation

Solution: $$eqalign{
& frac{5}{6} = left( {frac{5}{6} imes 100}
ight)\% cr
& ,,,,,, = 83frac{1}{3}\% cr
& frac{2}{3} = left( {frac{2}{3} imes 100}
ight)\% cr
& ,,,,,, = 66frac{2}{3}\% cr
& frac{2}{5} = left( {frac{2}{5} imes 100}
ight)\% cr
& ,,,,,, = 40\% cr
& frac{1}{4} = left( {frac{1}{4} imes 100}
ight)\% cr
& ,,,,,, = 25\% cr
& frac{2}{{11}} = left( {frac{2}{{11}} imes 100}
ight)\% cr
& ,,,,,,,,, = 18frac{2}{{11}}\% < 20\% cr} $$

[#414] Twelve percent of Kaushal's monthly salary is equal to sixteen percent of Nandini's monthly salary. Sanal's monthly salary is half that of Nandini's. If Sonal's annual salary is Rs. 1.08 lacs, what is Kaushal's monthly salary ?
Correct Answer

(C) Rs. 24000

Explanation

Solution: Sonal's annual salary = Rs. 108000 ∴ Sonal's monthly salary = Rs. $$left( {frac{{108000}}{{12}}}
ight)$$ = Rs. 9000 Nandini's monthely salary = Rs. (9000 × 2) = Rs. 18000 Let Kaushal's monthly salary be Rs. x Then, 12% of x = 16% of 18000 ⇒ $$frac{{12}}{{100}}$$x = $$left( {frac{{16}}{{100}} imes 18000}
ight)$$ ⇒ $$frac{{12}}{{100}}$$x = 2880 ⇒ x = $$left( {frac{{2880 × 100}}{{12}}}
ight)$$ ⇒ x = 24000

[#415] 30% of a number when subtracted from 91, gives the number itself. Find the number.
Correct Answer

(D) 70

Explanation

Solution: Let the number be x
According to the question, 91 - $$frac{{30{ ext{x}}}}{{100}}$$ = x 9100 - 30x = 100x Or, 9100 = 130x Or, x = $$frac{{9100}}{{130}}$$ Hence, x = 70