Fractions in Disguise Class 8 Short Question Answer

Fractions in Disguise Class 8 Short Question Answer

Fractions in Disguise Class 8 Short Question Answer

Question 1.

72% of 25 students are good in mathematics. How many are not good in mathematics ?

Solution:

72% of 25 students are good in mathematics.

∴ (100 - 72)%, i.e., 28% of 25 students are not good in mathematics.

Thus, their number = 28% of 25

= [latex]\left(\frac{28}{100} \times 25\right)[/latex]

= 7 students.

Question 2.

8% children of a class of 25 like getting wet in the rain. How many children like getting wet in the rain ?

Solution:

Out of 100, 8 children like getting wet in rains. Therefore, out of 25, the number of children that like getting wet in rains

= [latex]\frac{8}{100}[/latex] × 25 = [latex]\frac{8}{4}[/latex] × 1 = 2.

Question 3.

9 is 25% of what number ?

Solution:

Let the number be a. Then,

25% of a = 9.

or [latex]\frac{25}{100}[/latex] × a or [latex]\frac{1}{4}[/latex] × a = 9

or a = 9 × 4 or a = 36.

∴ The required number is 36.

Question 4.

Convert the given decimal fraction to per cents.

(a) 0.65

(b) 2.1

(c) 0.02

(d) 12.35

Solution:

(a) 0.65 = [latex]\left(\frac{0.65 \times 100}{100}\right)[/latex] = [latex]\frac{65}{100}[/latex] = 65%

(b) 2.1 = [latex]\left(\frac{2.1 \times 100}{100}\right)[/latex] = [latex]\frac{210}{100}[/latex] = 210%

(c) 0.02 = [latex]\left(\frac{0.02 \times 100}{100}\right)[/latex] = [latex]\frac{2}{100}[/latex] = 2%

(d) 12.35 = [latex]\left(\frac{12.35 \times 100}{100}\right)[/latex] = [latex]\frac{1235}{100}[/latex] = 1235%.

Question 5.

In a city, 30% are females, 40% are males and remaining are children. What per cent are children ?

Solution:

In a city,

Percentage of female = 30%

Percentage of male = 40%

∴ Percentage of children = (100 - 30 -40)%

= 30%.