(i) what per cent of 120 is 90 ?
(ii ) what per cent of 1 kg is 5 g ?
(iii) what per cent of 3.5 L is 150 mL ?

Answer

Let's solve the problems step by step.

### (i) What percent of 120 is 90?

1. **Set up the equation**: Let \( x \) be the percentage we want to find. We can express this as:
\[ \frac{x}{100} \times 120 = 90 \]

2. **Rearrange the equation**: Multiply both sides by 100 to eliminate the fraction:
\[ x \times 120 = 90 \times 100 \]
\[ x \times 120 = 9000 \]

3. **Solve for \( x \)**: Divide both sides by 120:
\[ x = \frac{9000}{120} \]

4. **Calculate**:
\[ x = 75 \]

5. **Conclusion**: Therefore, \( 90 \) is \( 75\% \) of \( 120 \).