Hi, I'm new to the forums and not sure if this post is in the right forum.

I have in total 10 questions that are absolutely doing my head in. If anyone could help me out and show me how to work these out, it'd be much appreciated.

1) In a class of 45 girls, all of whom have chosen to study either history or psychology, or both, 40 are studying psychology and 25 are studying history. How many are studying both?

A.12 B.20 C.22 D.14 E.8

2) A horse breeder owns 25 horses. If there are twice as many black horses as chestnuts, but the number of brown horses is one more than black and chestnut horses together, how many black horses are there?

A.8 B.12 C.9 D.6 E.10

3) A planes compass is upset by a storm so that the needle which should point north now points to the west. If the pilot flies south by his compass what is his true direction?

A.North B.South-West C.East D.West E.North West

4) In a bag of fruit I have as many oranges as apples and twice as many mandarines as oranges. If I have 15 pieces of fruit how many mandarines do I have?

A.6 B.8 C.2 D.7 E.4

5) A factory employed 120 men. If 25% of those were retrenched and 20% of those who remained were retrained for new jobs within the factory, how many men remained at their original job?

A.72 B.45 C.48 D.20 E.66

6) Two trains, X and Y, leave their common origin together on a 1200km trip. Train X travels three times slower than Y. How far has X to go when Y reaches its destination?

A.300km B.600km C.900km D.800km E.100km

7) I have a bag of oranges and bananas but 20% are bad. If there are 10 pieces of rotten fruit and there are 25 good oranges, how many good bananas are there?

A.15 B.20 C.25 D.30 E.35

8) In a class one-third of the students do psychology, two-fifths do economics and the remaining 8 do physics. How many students are there in the class?

A.12 B.30 C.18 D.24 E.16

9) In a garden, one-quarter of the trees are apple trees and one-third are orange trees. The remaining trees are lemons, grown as wind shelter. What is the number of apple trees in the garden?

A.1 B.2 C.3 D.4 E.5

10) In a crowded bus, five-eigths of the people had seats. Two-thirds of the remainder held straps to support them and the other 2 people had to use the seat back for support. How many people were on the bus?

A.15 B.12 C.16 D.24 E.10

Any help would be very much appreciated, thanks