Write t for ture and false for each of the following:
(1) `3/4` as rate per cent is `75%`
(2) `12.1/2%` experesseed as afraction is `1/8`
(3) `2:5=25%`
(4) `80% of 450 =360.
(5) 20% of 1liter =200ml

Answer

### Step-by-Step Solution:

**(1) Is `3/4` as a rate per cent `75%`?**

To convert `3/4` into a percentage:
- Multiply `3/4` by `100`.

\[ \frac{3}{4} \times 100 = 75 \]

Thus, `3/4` is indeed `75%`.
**Answer: True (T)**

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**(2) Is `12.1/2%` expressed as a fraction `1/8`?**

First, convert `12.1/2%` into an improper fraction:
- `12.1/2%` is `12.5%` which can be written as `12.5/100`.

Next, convert `12.5` into a fraction:
- `12.5 = 12 + 0.5 = \frac{25}{2}`.

So, we have:

\[ \frac{25}{2} \div 100 = \frac{25}{200} \]

Now, simplify `25/200`:

\[ \frac{25 \div 25}{200 \div 25} = \frac{1}{8} \]

Thus, `12.1/2%` is indeed `1/8`.
**Answer: True (T)**

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**(3) Is `2:5` equal to `25%`?**

To find the percentage of `2:5`, convert it to a fraction:

\[ \frac{2}{5} \times 100 \]

Calculating this gives:

\[ \frac{2 \times 100}{5} = \frac{200}{5} = 40 \]

Thus, `2:5` is equal to `40%`, not `25%`.
**Answer: False (D)**

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**(4) Is `80% of 450 = 360`?**

To find `80% of 450`, calculate:

\[ \frac{80}{100} \times 450 = \frac{80 \times 450}{100} \]

This simplifies to:

\[ \frac{36000}{100} = 360 \]

Thus, `80% of 450` is indeed `360`.
**Answer: True (T)**

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**(5) Is `20% of 1 liter = 200 ml`?**

First, convert `1 liter` to milliliters:

\[ 1 \text{ liter} = 1000 \text{ ml} \]

Now calculate `20% of 1000 ml`:

\[ \frac{20}{100} \times 1000 = \frac{20 \times 1000}{100} = 200 \text{ ml} \]

Thus, `20% of 1 liter` is indeed `200 ml`.
**Answer: True (T)**

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