Quiz 1

Explanation:
Let their marks be (x+9) and x.
Then,X+9=\frac{56}{100}(x+9+x)
25(x + 9) = 14(2x + 9)
3x = 99
x=33

So the marks are 33 and 42.

Explanation:
50% of 60=\frac{50}{100}\times 60=30
and,
20% of 70=\frac{20}{100}\times 70=14

=30-14
=16

Hence,50% of 60 will be 16 greater than 20% of 70

Explanation:
Clearly, the numbers which have 1 or 9 in the unit's digit, have squares that end in the digit 1. Such numbers from 1 to 70 are 1, 9, 11, 19, 21, 29, 31, 39, 41, 49, 51, 59, 61, 69.

Number of such number =14

Required percentage=\frac{14}{70}\times 100%
=20%

Explanation:
Let the number be x.
Then error=(5x/3 - 3x/5)*100*(3/5x)
Error%=64%

Explanation:
No. of valid votes=80% of 7500
=6000

Therefore valid votes polled by other candidate=45% of 6000
=\frac{45}{100}\times 6000
=2700

Explanation:
Total no. of votes polled=(1136+7636+11628)=20400

Therefore,Required percentage=\frac{11628}{20400}\times 100% =57%

Explanation:
Let the sum paid to Y per week be z.
Then,z+120% of z=550
z+\frac{120z}{100}=550
\frac{11z}{5}=550
z=\frac{550\times 5}{11}
=250

Explanation:
Let the amount taxable purchases be Rs. x.
Then,6% of x =\frac{30}{100}
x=(\frac{30}{100})(\frac{100}{6})
x=5

Hence,cost of tax free items=Rs.[25-(5+0.30)]=Rs.19.70

Explanation:
increase in 10 years=(262500-175000)=87500.
Increase %  = \frac{87500}{175000}\times 100 = 50%
therefore required average= \frac{50}{10}%
=5%

Explanation:
Let total number of workers be= 100
Technicians= 40%
Non-technicians= 60%

No. of permanent technician workers=40*(60/100)=24

and no of permanent Non-technicians=60*(40/100)=24

total no of permanent technicians and non-technicians=24 + 24 = 48

 

Hence,no. of non-permanent workers=> 100 - 48 = 52%”