F.1數學問題~~急急急!請幫幫手!

1.In alloy A and alloy B, there are 30%and 40% of iron in weight

respectively.Now a new alloy is formed by 6 kg of alloy A and 2 kg of

alloy B.In a new alloy,

(a)what is the weight of iron?

Weight of iron

= 6*30%+2*40%

= 1.8+0.8

= 2.6kg

(b)what percentage of weight is iron?

Percentage of weight of the iron

= 2.6/(6+2) *100%

= 32.5%

2.There were 546 male candidates and 275 female candidates passing a

public examination,which represent 65% of the male candidates and 55%

of the female candidates respectively participating in the

examination.Find the number of candidates participating in the

examination.

The number of candidates participating in the examinations

= 546/65%+275/55%

= 840+500

= 1340

3.There are 640 books in the novel section of a library.65% of them are

in English and the rest are in Chinese.Now 160 extra Chinese novels are

brought to the section.

(a)How many Chinese novels are brought to the section?

Number of Chinese novels are brought to the section

= 640*(1-65%)+160

= 224+160

= 384

(b)What percentage of the novels are in Chinese?

Percentage of the novels are in Chinese

= 384/(640+160)*100%

= 48%

(c)By what percentage are the English novels more than the Chinese novels?

Percentage are the English novels more than the Chinese novels

= 1-48%-48%

= 52%-48%

= 4%