# Making Maths Count

## Maths Week Scotland – New Outfit

September 12, 2018 by John Swinney MSP 4 Comments

I hope you are enjoying the Maths Week Scotland daily puzzles. Here is the puzzle for day three. There is more than one way to solve this. Good luck!

**New Outfit**

Asif is shopping for a new outfit for a special occasion. He needs a shirt, a pair of trousers and a pair of shoes. Once he has picked out the items he likes and checked the prices he realises that:

- if he doesn’t buy the shirt, he can get the other items for £115
- if he doesn’t buy the trousers, he can get the other items for £100
- if he doesn’t buy the shoes, he can get the other items for £75.

But, of course, he needs the shirt, the trousers and the shoes. So what will he have to pay for all of them?

**Solution to: New Outfit**

Answer: £145

Here are two possible ways to reach the answer:

1.

The trousers and shoes cost £115.

The shirt and the shoes cost £100.

So the trousers cost £15 more than the shirt.

But the trousers and the shirt cost £75. So we need two numbers that add to 75 but which differ by 15. They are 45 and 30.

So the shirt costs £30 and the cost of all three items is £115 + £30 = £145.

2.

Imagine that Asif and his friend, let’s call him Alistair, go together and buy a shirt, a pair of trousers and a pair of shoes each. As strange as it seems, their tastes are so similar that they select exactly the same items. Together they buy:

shirt + trousers | £75 |

shirt + shoes | £100 |

trousers + shoes | £115 |

£290 |

They have paid £290 between them, which is £145 each.

Don’t forget to come back tomorrow for the next Maths Week Scotland puzzle!

Tags: Education, John Swinney, Maths Week

x(shirt), y(trousers), z(shoes)

(y+z) = 115

(x+y) = 75

(x+z) = 100

2(x+y+z) = 290

x+y+z = 145

x = 145 – (y+z) = 145 – 115 = 30

y = 145 – (x+z) = 145 – 100 = 45

z = 145 – (x+y) = 145 – 75 = 70

More ways to do maths . This is one more.

Denny High S1 say the answer is £145

P6-7 from Turriff Primary School worked it (on their own) as £145

Got it 150