Periyar University 2008 B.E Electronics

Sol: let no. of fish x catches=p

No. caught by y =r

r=5p.

provided r+p=42

Then p=7, r=35


14) 3 companies are working independently and receiving the savings 20%, 30%, 40%. If the companies work combine, what will be their net savings?

Sol: Suppose total income is 100

So amount x is getting is 80

y is 70

z =60

Total=210

But total money is 300

300-210=90

So they are getting 90 rs less

90 is 30% of 300 so they r getting 30% discount




15) The ratio of incomes of C and D is 3:4.the ratio of their expenditures is 4:5.Find the ratio of their savings if the savings of C is 1 fourths of his income?

Sol: incomes: 3:4

Expenditures: 4:5

3x-4y=1/4(3x)

12x-16y=3x

9x=16y

y=9x/16

(3x-4(9x/16))/ ((4x-5(9x/16)))

Ans: 12/19





16)If A can copy 50 pages in 10 hours and A and B together can copy 70 pages in 10 hours, how much time does B takes to copy 26 pages?

Sol: A can copy 50 pages in 10 hrs.

=>A can copy five pages in 1hr. (50/10)

Now A & B can copy 70 pages in 10hrs.

Thus, B can copy 90 pages in 10 hrs. [Eqn. is (50+x)/2=70, where x--> no. of pages B can copy in 10 hrs.]

So, B can copy nine pages in 1hr.

Therefore, to copy 26 pages B will need almost 3hrs.

Since in 3hrs B can copy 27 pages




17) A can copy 50 papers in 10 hours while both A & B can copy 70 papers in 10 hours. Then for how many hours needed for B to copy 26 papers?

ANS: 13


18) A is twice efficient than B. A and B can both work together to complete a work in seven days. Then obtain in how many days A alone can complete the work?

ANS: 10.5 (11)





19) A finish the work in 10 days. B is 60% efficient than A. So how days does B take to finish the work?

Ans: 100/6 (4 days)




20) A finishes the work in 10 days & B in eight days individually. If A works for only six days then how many days should B work to complete A's work?

Ans: 3.2 days (4 days)




21) A man, a woman, and a child can do a piece of work in six days. Man only can do it in 24 days. Woman can do it in 16 days and in how many days child can do the identical work?

Earning:   Approval pending.