$1\dfrac{3}{4}$ hours equals how many minutes?

Hint:
Here they have given a mixed fraction in terms of hours and asking us to find corresponding time in minutes. Whether they have given in fraction, decimal or anything it does not matter, if we know $1hour = 60 \text{minutes}$ then we can easily convert the given number in terms of hours just by multiplying with $60$.

Complete step by step solution:
In the given question they have asked to convert from hours to minutes. We know that the time can be represented in terms of hours, minutes, seconds, and so on. These are all the units of the time.
We also know that one hour is equal to $60$ minutes and one minute is equal to $60$ seconds. Knowing this much is enough to solve the given time in hour to minute form.
The given time is $1\dfrac{3}{4}$ hours now if we multiply the given time with $60$ we will get the time in terms of minutes, which can be written as follows
$1\dfrac{3}{4} = 1 \times 60 + \dfrac{3}{4} \times 60$
On simplifying the above expression, we get
$ \Rightarrow 1\dfrac{3}{4} = 60 + 45$
Therefore, we get
$ \Rightarrow 1\dfrac{3}{4} = 105$.
Now the given time $1\dfrac{3}{4}$ hours is converted to $105$ minutes.
As we have converted from hours to minutes the unit will also change now. Therefore $1\dfrac{3}{4}$ hours is equal to $105$ minutes.

Note:
Whenever converting from hours to minutes we can directly multiply the given value with a conversion number that is by $60$ we can easily convert to whichever form they have asked for. The given value may be in decimal, fraction or mixed fraction whatever you can directly do the calculation, or if you want you can convert mixed fraction to fraction or decimal and they do the calculation.