question_answer

In a primary school, the parents were asked about the number of hours they spend per day in helping their children to do homework. There were 90 parents who help for \[\frac{1}{2}\]hr to\[1\frac{1}{2}\]hr. The distribution of parents according to the time for which, they said they helped is given in the adjoining figure, 20% helped for more than 1-hr per day. 30% helped for \[1\frac{1}{2}\] hr to \[1\frac{1}{2}\]hr; 50% did not help at all Using this, answer the following :

(a) How many parents were surveyed?

(b) How many said that did not help?

(c) How many said that they helped for more than \[1\frac{1}{2}\] hours?

Answer:

Let us suppose that there are x parents.

90 parents who help for \[\frac{1}{2}\]hr to \[1\frac{1}{2}\]hr.

They show the percentage is 30%, then according to formula.

Percentage value = The percentage of whole value

90 = 30% of x

\[90=\frac{30x}{100}\]

\[\frac{90\times 100}{3}=x\]

x = 300

There are 300 parents:

20% helped for more than\[1\frac{1}{2}\] hr. per day.

Again, according to condition,

Percentage value = Percentage of whole value

= 20% of x

\[=\frac{20}{100}\times 300\]

Percentage value = 60 parents who helped their children more than \[1\frac{1}{2}\] hr per day 50% did not help at all.

Again, using formula,

Percentage value = Percentage of whole value

= 50% of x

\[=\frac{50}{100}\times 300\]

Percentage value = 150 parents did not help at all

(a) 20% helped for more than \[1\frac{1}{2}\] hr per day + 30% helped for \[\frac{1}{2}\] hr to \[1\frac{1}{2}\] hr per day = The value of 20% + The value of 30% + The value of 50% + 50% did not help = 60 parents who help their children more than\[1\frac{1}{2}\]hr. + 90 parents who help their children \[\frac{1}{2}\] hr to\[1\frac{1}{2}\] hr. + 150 parents who did not help = 300 parents who help their children

(b) The value of 50% parents they said did not help = 150

(c) The value of 20% who said that they help their children more than \[1\frac{1}{2}\] hr = 60 parents