There are 100 toffees in a packet. How many toffees are there in 25 such packets?
(a) $25\times100$
(b) $25+100$
(c) $100\div 25$
(d) $100-25$

Hint: In this question we will first find toffees in 2 packets, then 3 and gradually go to 25 packets.

Complete step-by-step answer:
According to the equation, one packet contains 100 toffees.
So, in two packets, we have, two times hundred toffees. That is $100+100$ toffees which is equal to $2\times 100$ toffees.
In 3 packets we will have $100+100+100$ toffees. Here, 100 comes three times. So, we have 3 times 100 toffees. This can be written as $3\times 100$ toffees.
In four packets we will have $100+100+100+100$ toffees. Here 100 comes four times. So, we will have 4 times 100 toffees.
This can be written as $4\times 100$.
Similarly, when we have 25 packets, we have 100 toffees 25 times. That is $100+100+...........+100$
Here 100 is added 25 times.
Therefore, we can write this as $100\times 25$ toffees.
Hence correct and is option (a).

Note: In this type of question, when we are given numbers of things in one unit and number of units are also given. Then the total number of things are always, number of units, number of things in one unit.