Maths

11 Plus Maths – Preparation and Information

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Uma
Posts: 22
Joined: Sat Jun 21, 2008 12:56 pm

Maths

Post by Uma »

Hi

Pls help to solve this.

To obtain the colour green that Jack wants to paint his room he mixes 11 liters of yellow with 1 liter blue.
Jack will need 5 liters of green.

How much blue paint will Jack need?

(a) 1 1/4 liters (1.25liters)
(b) 1 1/2 liters (1.5 liters)
(c) 1 3/4 liters (1.75 liters)
(d) 2 1/4 liters (2.25 liters)

Thanks

Uma
WP
Posts: 1331
Joined: Thu Jan 03, 2008 9:26 am
Location: Watford, Herts

Post by WP »

The recipe makes 12 litres of green paint, so to make 5 litres, he needs 5*11/12 = 4 7/12 litres of yellow and 5/12 litres of blue. However this is not one of the alternatives offered.
doodles
Posts: 8300
Joined: Tue Oct 27, 2009 9:19 pm

Post by doodles »

Not sure that the answer is one offered.

Receipe makes 12 litres of paint. Jack needs 5 litres which is slightly under half of the receipe. Therefore, he will need slightly under 1/2 litre of blue - there is no answer that small!

Or am I being totally stupid. We were always taught to roughly estimate the answer before working out so we knew if we were completely off track or not.
Knowledge is knowing that a tomato is a fruit, wisdom is not putting it in a fruit salad !
rosered100

Post by rosered100 »

Perhaps it should be 15 litres of green that he needs. That would work then at 1.25l of blue
Uma
Posts: 22
Joined: Sat Jun 21, 2008 12:56 pm

Post by Uma »

May be typing error on the book :(

but the answer 1.25 is correct.


Thanks

Uma
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