Percentage - Study Mode
[#291] A shepherd had n goats in the year 2000. In 2001 the no. of goats increased by 40%. In 2002 the no. of goats declined to 70%. In 2003 the no. of goats grew up 30%. In 2004, he sold 10% goats and then he had only 34,398 goats. The percentage increase of the no. of goats in this duration was :
Correct Answer
(B) 14.66%
Explanation
Solution: There is no need of the number of goats given i.e. 34,398. Initially, let there be 100 goats. Then 100 == 40% ↑==> 140 == 30%↓(declined to 70%) ==> 98 == 30%↑ ==> 127.4 == 10%↓(sold) ==> 114.66 Hence, % increase = 14.66% [As 100 becomes 114.66]
[#292] In an office in Singapore there are 60% female employees. 50 % of all the male employees are computer literate. If there are total 62% employees computer literate out of total 1600 employees, then the no. of female employees who are computer literate ?
Correct Answer
(C) 672
Explanation
Solution: Total employees = 1600 Female employees, 60% of 1600 $$ = frac{{60 imes 1600}}{{100}} = 960$$ Then male employees = 640 50% of male are computer literate, = 320 male computer literate 62% of total employees are computer literate, $$ = frac{{62 imes 1600}}{{100}} = 992$$ xa0 xa0 computer literate Thus, Female computer literate = 992 - 320 = 672 Alternatively : Let 60% employees are female and 40% are male Then, 20% of male are computer literate and 42% are female computer literate Female computer literate $$ = frac{{1600 imes 42}}{{100}} = 672$$
[#293] The price of a car depreciates in the first year by 25% in the second year by 20% in third year by 15% and so on. The final price of the car after 3 years, if the present cost of the car is Rs. 10,00,000 :
Correct Answer
(D) 5,10,000
Explanation
Solution: Price after third depreciation, 100 ==25%↓ ==> 75 == 20%↓==>60 == 15% ↓ ==> 51 The price will be, = Rs. 5,10,000 Alternatively : 1000000 × 0.75 × 0.80 × 0.85 = Rs. 5,10,000
[#294] In an election, 30% of the voters voted for candidate A whereas 60% of the remaining voted for candidate B. The remaining voters did not vote. If the difference between those who voted for candidate A and those who did not vote was 1200, how many individuals were eligible for casting vote in that election ?
Correct Answer
(C) 60000
Explanation
Solution: Let the number of persons eligible to vote be x Then, votes who voted for A = 30% of x Votes who voted for B = 60% of (70% of x) = $$left( {frac{{60}}{{100}} imes frac{{70}}{{100}} imes 100}
ight)$$ xa0 % of x = 42% of x Voters who did not vote = [100 - (30 + 42)]% of x = 28% of x ∴ 30% of x - 28% of x = 1200 ⇒ 2% of x = 1200 ⇒ x = $$left( {frac{{1200 × 100}}{{2}}}
ight)$$ ⇒ x = 60000
[#295] x% of x is the same as 10% of
Correct Answer
(B) $$frac{{{x^2}}}{{10}}$$
Explanation
Solution: Let x% of x = 10% of y Then, $$eqalign{
& Rightarrow frac{x}{{100}} imes x = frac{{10}}{{100}} imes y cr
& Rightarrow y = frac{{{x^2}}}{{100}} imes 10 cr
& Rightarrow y = frac{{{x^2}}}{{10}} cr} $$