Bond Assessment Papers Bk1 - Paper 9 Qu31-34

[madintheattic]

Could someone tell me how to work this out? It's the second time a question like this has come up and I've not been able to explain it!

3 pencils and 4 ballpoint pens cost £1.70.
3 pencils and 2 ballpoint pens cost £1.30.

Use this information to find the cost of:

2 ballpoint pens?
1 ballpoint pen?
3 pencils?
1 pencil?

Would greatly appreciate the help - have a feeling it's really obvious and I'm just being dim! Thanks

[Okanagan]

3 pencils and 4 ballpoint pens cost £1.70.
3 pencils and 2 ballpoint pens cost £1.30.

Use this information to find the cost of:

2 ballpoint pens?
1 ballpoint pen?
3 pencils?
1 pencil?

3 pencils and 4 ballpoint pens cost 40p more than 3 pencils and 2 ballpoint pens, therefore 2 ballpoint pens cost 40p
-> 1 ballpoint pens costs 20p
3 pencils and 2 ballpoint pens cost £1.30, and we know that 2 ball point pens cost 40p, therefore 3 pencils cost 90p
-> 1 pencil costs 30p

[madintheattic]

Thank you very much, I see it now.

I still can't seem to apply it to this question in one of the 11+ DIY Papers though -

6 JELLYS and 3 GALAXY CARAMEL cost £7.11. 3 GALAXY CARAMEL and 6 CURLY WURLY cost £6.57.
How much does 1 JELLYS, 1 GALAXY CARAMEL and 1 CURLY WURLY cost?

I've tried and tried! Please put me out of my misery...

[Okanagan]

6 JELLYS and 3 GALAXY CARAMEL cost £7.11.
3 GALAXY CARAMEL and 6 CURLY WURLY cost £6.57.
How much does 1 JELLYS, 1 GALAXY CARAMEL and 1 CURLY WURLY cost?

Add them together and you get
6 JELLYS + 3 GALAXY CARAMEL + 3 GALAXY CARAMEL + 6 CURLY WURLY costs £7.11 + £6.57
which simplified is
6 JELLYS + 6 GALAXY CARAMEL + 6 CURLY WURLY costs £13.68
divide £13.68 by 6 to get the answer £2.28