中一英文數學題~急~

請唔該寫出條數式,詳細的解釋(點解會有呢個answer)和題目的中文解釋,thx
1)When the mintues hand of a clock moves 40 mintues , the angle it turned is ...

the answeris 240°

2)A store is on sale , and all goods are sold at a discount of 5% . If a person pays by cash , a further discount of 5% would be awarded.
Find the actual discount percent for cash payment.

the answer is 9.75%

3)If a is lighter than by 20%,the B is heavier than A By ...

the answer is 25%(不用中文解釋)

4) Selling at a loss of 10%,the price ofa watch is $540 .Selling at a gain of 20%,the price is ...

the answer is $720

5)two identical cubes are stuck together to form a cubiod .If the surface area of 1 cube is 12 cm2 ,find the total surface area of the cuboid

the answer is 20cm2

我exam個陣成日看不明條題說d咩,有d咩方法(除咗improve 英文)可以估到個meaning of the word?or help我看得明條題,我exam個陣,個腦就一片空白