**Today’s Challenge**

The numbers **21 to 29 inclusive** must be allocated to each letter below so that each number satisfies the condition given on the line and only appears once:

- (a) even number,
- (b) factor of 144,
- (c) power of 3,
- (d) prime number,
- (e) digits which differ by 1,
- (f) exactly 3 factors,
- (g) multiple of 7,
- (h) equal to the sum of all its factors (except the number itself),
- (i) 2nd digit is greater than its 1st digit.

Remember, the numbers **21 to 29** should only appear once each.

**The 7puzzle Challenge**

The playing board of **the 7puzzle game** is a 7-by-7 grid containing 49 different numbers, ranging from **2 **up to **84**.

The 1st & 7th rows of the playing board contain the following fourteen numbers:

2 4 9 11 14 15 22 24 27 30 40 70 72 77

Which odd number, when 21 is added to it, becomes a square number?

**Make 18 Challenge**

Can you arrive at 18 by inserting 2, 3, 4 and 6 into the gaps on each line?

- ◯×◯–◯×◯ = 18
- ◯÷◯×◯×◯² = 18
- (◯÷◯)³×√◯÷◯ = 18

**Answers **can be found **here**.

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