Percentage - Study Mode

[#476] ? % of 450 + 46% of 285 = 257.1
Correct Answer

(B) 28

Explanation

Solution: Let x% of 450 + 46% of 285 = 257.1 $$ Rightarrow left( {frac{x}{{100}} imes 450}
ight) + left( {frac{{46}}{{100}} imes 285}
ight)$$ xa0
xa0 $$ = 257.1$$ $$eqalign{
& Rightarrow frac{{9x}}{2} = 257.1 - 131.1 cr
& Rightarrow frac{{9x}}{2} = 126 cr
& Rightarrow x = frac{{126 imes 2}}{9} cr
& Rightarrow x = 28 cr} $$

[#477] Anand has drawn an angle of measure 45° 27' when he was asked to draw an angle of 45° . The percentage error in his drawing is ?
Correct Answer

(B) 1%

Explanation

Solution: Error = (45° 27' - 45° ) = 27' Accurate measure = 45° = (45 × 60)' = 2700' ∴ Percentage error : $$eqalign{
& = left( {frac{{27}}{{2700}} imes 100}
ight)\% cr
& = 1\% cr} $$

[#478] Solve this : 15% of 578 + 22.5% of 644 = ?
Correct Answer

(B) 231.6

Explanation

Solution: 15% of 578 + 22.5% of 644 $$ = left( {frac{{15}}{{100}} imes 578}
ight) + $$ xa0 $$left( {frac{{225}}{{10}} imes frac{1}{{100}} imes 644}
ight)$$ $$eqalign{
& = 86.7 + 144.9 cr
& = 231.6 cr} $$

[#479] Solve : 105.27% of 1200.11 + 11.80% of 2360.85 = 21.99% of (?) + 1420.99
Correct Answer

(D) 550

Explanation

Solution: 105.27% of 1200.11 + 11.80% of 2360.85 = 21.99% of (?) + 1420.99 ⇒ 105% of 1200 + 12% of 2360 = 22% of (?) + 1421 ⇒ $$frac{{105 imes 1200}}{{100}} + frac{{12 imes 2360}}{{100}} = $$ xa0 xa0 $$frac{{22 imes (?)}}{{100}}$$ xa0 $$ + ,1421$$ $$ Rightarrowfrac{{22 imes (?)}}{{100}} = 1260 + 283.30$$ xa0 xa0 xa0 $$ - ,1421$$ $$eqalign{
& Rightarrow frac{{22 imes (?)}}{{100}} = 1543 - 1421 cr
& Rightarrow frac{{22 imes (?)}}{{100}} = 122 cr
& herefore (?) = frac{{122 imes 100}}{{22}} cr
& Rightarrow (?) = frac{{122 imes 50}}{{11}} cr
& Rightarrow (?) = 554.5,, (approximate,, 550) cr} $$

[#480] 31% of employees pay tax in the year 2008. Non-tax paying employees are 20700. The total number of employees is :
Correct Answer

(C) 30000

Explanation

Solution: Percentage of Non-tax paying employees = (100 - 31)% = 69% 69% of total employees = 20700 Total employees = $$frac{20700}{69}$$ × 100 = 30000