# Question 16 , 17 & 18

**Question 16: In a class consisting of boys and girls there are 30 students. Girls are the third fifth of total number. How many boys are there in the class?**

**FPSC AD IB 2017 2nd batch**

**Solution:**

Let the number of boys in the class is ‘x’;

Girls are 3/5 of 30 students. so;

according to question;

but boys are ‘x’ and girls are 3/5 of 30 students, so;

so boys are 12

**Question 17: Find the ‘x’ value where x:3=4:8**

**FPSC AD IB 2017-2ns batch**

**Solution**

We can write given expression as below as well;

**Question 18: Evaluate 32-15×2+3**

**FPSC AD IB 2017-2ns batch**

**Solution: **

First we perform division, then multiplication, then addition, and then subtraction operation, so;