Maths

firsttimermum · Post by **firsttimermum** » Thu May 07, 2009 12:10 pm

Hi !

Wondering if anyone can solve this problem for me, the answer is simple but somehoe I can't see it..

Petrol tank is 3/4 full.After 75 litres have been drawn off it is 3/5 full.
What is the capacity of the tank?

I don't think it is worded very well so if someone can help it would really be appreciated.

Regards,

FTM

solimum · Post by **solimum** » Thu May 07, 2009 12:17 pm

Think of the tank divided into 20ths

3/4 is 15/20

3/5 is 12/20

The difference is 3/20 - which equates to the 75 litres

So 1/20 of the tank is 25 litres

So the tank is 500 litres (20X25)

firsttimermum · Post by **firsttimermum** » Thu May 07, 2009 7:32 pm

Thanks for that ! To think I did A LEVEL Maths and did well in it!! Sometimes even the simple things can confuse you. Thankyou really appreciate the answer.

Regards,

FTM

Rose petal · Post by **Rose petal** » Sat May 09, 2009 11:11 am

I got the same answer but in a different way.

3/4 = 75%
3/5 = 60%

This drop of 15% is 75 litres.

Find 1% of the tank (75/15) = 5

The full tank is therefore 5 x 100 = 500 litres.

Rose Petal