A combination lock has a code consisting of 3 numbers, each of which can be 0 to 39, with numbers repeated. Jillian says that there are only 120 possible codes. Is Jillian correct?

There are 64,000 possible codes. Jillian is incorrect, since he added the possible options in each trial, instead of multiplied them(he did 40+40+40 instead of 40*40*40).

Step-by-step explanation:

From 0 to 39, there are 40 numbers.

The code has three values:

V1 - V2 - V3

When we have n trials with m possible options, the total number of opitons is:

In this question:

3 trials(values), with 40 options. So

There are 64,000 possible codes. Jillian is incorrect, since he added the possible options in each trial, instead of multiplied them(he did 40+40+40 instead of 40*40*40).

13

step-by-step explanation:

169-1=168

168-3=165

165-5=160

160-7=153

153-9=144

144-11=133

133-13=120

120-15=105

105-17=88

88-19=69

69-21=48

48-23=25

25-25=0

since it took 13times to completely subtract it hence its square root is 13

step-by-step explanation:

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