# plz help on a simple problem

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• May 7th 2010, 12:04 AM
mathnoob123
plz help on a simple problem
i don't know where to post this thread, if i posted it wrong plz tell me ...

My Question is ... as you can see in the first image, i marked my doubt with red ink of problem 3.01, i wanna know how "3/48" came ...

and in the second image, in the problem 3.07, i wanna know how the 3+2/60 came and also in the problem 3.08, how did 5/24 came ...

plz guys help me out ... i'm preparing for an entrance exam

Cheers :)
• May 7th 2010, 12:12 AM
hekticity
1)

Cross multiply.

1/24 x 1/48
= (1x48) + (1x24) / (24 * 48)
= 72/1152
= 3/48
• May 7th 2010, 12:19 AM
hekticity
Again cross multiple..

1/20 + 1/30
= (1x30) + (1x20) / (20x30)
= 30 + 20 / 600 (crossing off the 0 you get)
= 3 + 2 / 60
= 5 / 60
= 1 / 12

You try the next one and post it on here, ill be more than happy to help!

If you dont mind me asking, what year are you in school ?
• May 7th 2010, 12:36 AM
mathnoob123
wow, thank you very much bro, you explained it crystal clear ...

and to say i am not in school ... lol i completed my graduation ... but iam a commerce student, just needed this maths for an entrance exam ... (BTW ... there's a lot of math which is eating my brain, tried it self but got dissed so i'm here in mathhelpforum... lol)

and you asked me to solve the 3rd one, so here it is ...

=(1x8)+(1x12)/(12x8)
=(8+12)/96
=20/96
=5/24

lol, thanx alot again bro, you should've seen me when i did the 3rd one ... haha ... cheers :)
• May 7th 2010, 01:34 AM
hekticity
Haha no problems mate, good to also see you attempting the questions and getting them right :)