Question

On Saturday afternoon, Armand sent m text messages each hour for 5 hours, and Tyrone sent p text messages each hour for 4 hours. Which of the following represents the total number of messages sent by Armand and Tyrone on Saturday afternoon?
(a) 9mp
(b) 20mp
(c) 5m + 4p
(d) 4m + 5p

Answer 1

Hint: We know that if we are given the value of 1 unit then we need to find the value of ‘n’ units by multiplying ‘n’ with the given value. Similarly, first of all, find the total messages sent by each one of them individually and then add them to get the final answer.

Complete step-by-step answer:
We are given that on Saturday afternoon, Armand sent m text messages each hour for 5 hours and Tyrone sent p text messages each hour for 4 hours. We have to find the total number of messages sent by Armand and Tyrone on Saturday afternoon.
Before proceeding with this question, we need to know the following concepts.
If we are given the value of a single unit, then we find the value of the necessary units by multiplying the value of a single unit by the number of units. For example, if a person does ‘p’ unit work in 1 hour, so in ‘n’ hours, he would do ‘np’ units of work.
Now let us consider the information given in the question. We are given that in an hour, the number of messages sent by Armand = m.
So, in 5 hours, number of messages sent by Armand = 5m……(i)
Also, we are given that in 1 hour, the number of messages sent by Tyrone = p
So, in 4 hours, the number of messages sent by Tyrone = 4p…..(ii)
So, we get the total number of messages sent by Armand and Tyrone on Saturday afternoon = Total number of messages sent by Armand in 5 hours + Total number of messages sent by Tyrone in 4 hours.
By substituting the values of RHS from equation (i) and (ii), we get,
Total number of messages sent by Armand and Tyrone on Saturday afternoon = 5m + 4p
So, we get the total number of messages sent by Armand and Tyrone on Saturday afternoon as (5m + 4p).
Hence, the option (c) is the right answer.

Note: In this question, students often make this mistake of misreading the question. In a hurry, students multiply 5 with p and 4 with m and get the answer as 5p + 4m that is option (d) which is incorrect because the correct answer is c. So, students are advised to first properly read and interpret the question and then only arrive at the answer.