a) Option 3 - She should have multiplied the total of all the choices.
b) The total number of amplifiers is 3
Step-by-step explanation:
Step 1 :
Given,
Number of models of stereos Antonio can select from = 4
Number of styles of speakers Antonio can select from = 3
Number of brands available for Adele = 2
Number of Transmission available for Adele = 3
Number of bumpers available for Adele = 3
Number of roofs available for Adele = 2
Step 2:
a)
From Step 1 , we can see that the total number of possible choices of vehicles Adele has = 2 × 3 × 3 × 2 = 36
Total possible choices as calculated by Adele = 2 + 3 + 3 + 2 = 10
Hence we can see that the error is that Adele has added the total possible choices instead of multiplying them.
So her error is as specified in option 3 - She should have multiplied the total of all the choices.
Step 4 :
b)
Given number of total available choices = 36
We need to find the number of amplifiers. Let x be the number of amplifiers.
As we know from step 1 the total available choices for Antonio are
4 × 3 × x = 36
=>12 x = 36
=> x = = 3
Hence the total number of amplifiers is 3
Step 5 :
Answer :
a) Option 3 - She should have multiplied the total of all the choices.
b) The total number of amplifiers is 3