Mensa Riddle?

Question

how many minutes is it before 12 noon if 16 minutes ago it was three times as many minutes after 9 am?

please provide explanation. thank you

i am not a Mensa member but i'm an enthusiast in feeding my brain with puzzles, riddle, science,and math.

Answer 1

Not ready for MENSA yet?

let y = the current time
and x = number of minutes before 12

12 o'clock can also be written as 720 minutes (after midnight)
9 o'clock can be written as 540 minutes

Thus y = 720 - x (it is x minutes before noon)
and y -16 = 540 + 3x (sixteen minutes ago it was 9 + 3 times x minutes)

subsituting, we get:
720 - x -16 = 540 + 3x
or
164 = 4x
x = 41 minutes

It is 41 minutes before 12 o'clock or 11:19
16 minutes ago it was 11:03, 123 minutes after 9 o'clock (or 41 x 3)

Answer 2

This was alittle tough because of the units of time but I got it.
You start at 9:00am. You know 3*x +16 + x equals noon. So the equation is

720=x+16+3x+540 with noon and 9:00am converted into minutes.
Then you solve for x and you realize that is x=41 minutes so it is 41 minutes before noon.
It works backwards
12:00-41=11:19
11:19-16=11:03
11:03-2hours 3 minutes=9:00am
Took me about 6 minutes to get it.

Answer 3

let's note a= how many minutes are till 12
i= the time we are now
between 9 AM and 12 noon there are 180 min
let's take 9 AM as the time 0 and 12 noon as 180 min
180-a=i
0+3*a+16=i => 180-a=0+3*a+16 => a=164/4 => a=41
THERE ARE 41 MIN TILL 12 NOON!!!!

Answer 4

x = time now

If we let 0 be the start of the time(which is under discussion) then after 3 hours or 3(60) minutes, it is 12 noon
3(60) - x = minutes before 12 noon

x - 16 = time 16 minutes ago
0 + (x - 16) = x - 16 = minutes after 9 am 16 minutes ago
3(60) - (x - 16) = minutes before 12 noon 16 minutes ago

3(60) - (x - 16) = 3(x - 16)
180 = 3(x - 16) + (x - 16)
180 = 4(x - 16)
45 = x - 16
x = 61

3(60) - x = 180 - 61 = 119 minutes

Trust me, the answer is correct!

^_^
^_^

Answer 5

Let x be the number of minutes before noon.
16 minutes ago, the number of minutes before
noon was x+16. The number of minutes after 9am is given by 180-(x+16).

So,
x+16 = 3*(180-x-16)
4x = 476
x = 119

So it must be 119 minutes before noon or 10:01am.

Check:
16 minutes ago (i.e. 9:45am), there were
3 times as many minutes after 9am (i.e. 45*3= 135 minutes)
as there were before noon 16 minutes ago (i.e. 119+16 = 135)

So it must be 119 minutes before noon.

The question is a bit confusing:

I am assuming that the minutes (16 min ago) are 3 times the minutes after 9am. One could assume that the minutes after 9am are 3 times as many minutes (16 mins ago) before 12.

If this is the case, then we have:

3(x+16) = (180-x-16)
3x + 48 = 164 - x
4x = 116
x = 29

29 minutes before noon.

Check:
11:31am
11:15am (16 minutes ago there were 45 minutes to noon)
From 9am to 11:15am there are 135 minutes.

135 minutes = 3 * 45 minutes

So in this case it would be 29 minutes to noon.

Therefore depending which way you interpret the question, your answer might be 119 or 29 minutes.

Answer 6

Let x be the number of minutes before 12 noon.

Then 180 - x -16 = 3x
180 is 3 hours in minutes

x = 41 minutes before 12 noon

Answer 7

It's 11:31: which is 16 minutes after 11:15 which is 3 times as many minutes after 9am as it was one times to 12 noon 16 minutes ago

Answer 8

let T be the minutes after 9'oclock

then it is (180 - T) minutes before noon

16 minutes ago it was three times the current time before noon so

T - 16 = 3*(180 - T)
T - 16 = 540 - 3*T
4*T = 556
T = 139

It is 139 minutes past 9:00

so it is 11:19

or 41 minutes until noon

Answer 9

11:03 a.m.

It is 57 minutes before noon.

Between 9 a.m. and noon, there is 180 minutes - 16 minutes= 164 min

If one section of time is 3X1 then there are 4 segments

164 min/4 = 41 min

noon - 16 min - 41 min = noon - 57 min = 11:03 a.m. which is 57 min before noon, to answer your question!

Did you know the answer because you are a Mensa member, or are you doing a Mensa quiz to find out if you qualify?

Answer 10

116 minutes.

I think.

3 times 16 is 48
So, 9:48 is our base, but that was 16 minutes ago.
So we add the current 16 minutes and get 10:04
From 10:04 to Noon is 116 minutes.

Right? Math was never my good subject.

Hope this helps.

Buddhadan