Chapter 6.4, Problem 29STP

To determine

To calculate:Number of students in classat present.

Answer to Problem 29STP

C. 30

Explanation of Solution

Calculation:

Let’s assumethere were $x$ number of students in the class last year.

One fourth of them were playing instruments, therefore, number of students playing instruments were $x/4$

Now, six students joined the class, Therefore, number of students now are, $x+6$

Out of them four are playing instruments, Therefore, number of students playing instruments are now, $\frac{x}{4}+4$

It is said that one third of the students are now playing an instrument,

  $\therefore \frac{x}{4}+4=\frac{1}{3}(x+6)$

  $\therefore x=24$

  $\therefore$ Students in the class at present are, $x+6=24+6=30$