Random Puzzles 

Workings

Hint
How many minutes are there between 2:00 and 7:00?

Answer
65 minutes.

Reasoning



We need to break down the five hours in the following way:

3 x Answer minutes past two o'clock 40 minutes Answer minutes before seven o'clock
Why? It is now Answer minutes before seven o'clock, and then we have the 40 minutes before that, and the remaining time was 3 x Answer minutes past two o'clock.

So, five hours = 5 x 60 = 300 minutes. We already know about the 40 minutes, so we have to share the remaining 260 minutes in the ratio 3:1, which gives 195:65 minutes. Or using algebra 4 x Answer = 300 − 40, so Answer = 65 minutes.

Therefore, the five hours is made up of:

195 minutes past two o'clock 40 minutes 65 minutes before seven o'clock
So, it's currently 65 minutes before 7:00 = 5:55.

Double-Checking
It is now 65 minutes before seven o'clock = 5:55, so 40 minutes ago it was 5:15, which is 195 minutes after 2:00 as required (as 65 x 3 = 195).

Workings

Hints
The first letters of the words are: N, C, C, C, E, H, O, C, L, M.

Answers
new + sag + ent = newsagent
cro + cod + ile = crocodile
col + lis + ion = collision
cla + ssr + oom = classroom
enc + our + age = encourage
hai + rbr + ush = hairbrush
oth + erw + ise = otherwise
clo + sen + ess = closeness
lig + htn + ing = lightning
mar + gar + ine = margarine

Workings

Hint
Row 3's missing letter is T.

Answer

Across: NEAR, BOWS, TREK, ZAPS
Down  : BANK, SPAR, ZERO, STEW
Boxes : BANS, WORE, PARK, ZEST

Other anagrams of these words are OK as long as they don't change the answer grid.

Workings

Hint
There are two different methods, one involves a cube root, and the other doesn't require a calculator.

Answer
9 x 11 x 13.

Reasoning #1
We're after three numbers that multiply together, so a good place to start is the cube root of 1,287, which is roughly 10.88.

Let's try dividing by the closest odd number to 10.88:

   1287 ÷ 11 = 117

We're now after whole divisors of 117. Trying the odd numbers either side of 11 might work.

Trying either 9 or 13 gives the answer:

   9 x 11 x 13 = 1,287

Trying the closest odd number to the cube root always works, and the other two numbers are the odd numbers either side.

Reasoning #2
We after three numbers that multiply together, but none of these can end in 5 (otherwise our answer would end in 0 or 5).

So, they can only end in 7, 9, 1 (e.g. 87, 89, 91), or 9, 1, 3 (e.g. 89, 91, 93).

However, if they ended in 7, 9, 1, the answer would end in 3 (because 7 x 9 x 1 = 63).

Therefore, they end in 9, 1, and 3 (because 9 x 1 x 3 = 27).

The first numbers we can try are 9, 11, 13:

   = 9 x 11 x 13
   = 99 x 13
   = 100 x 13 − 13
   = 1300 − 13
   = 1,287

A calculator is not required!