Question 888266
2.Padma purchased 30 kg of rice at the rate of tk 17.50 per kg and 30 kg rice at a certain rate.
 He mixed the two and sold the entire quantity at the rate of tk 18.60 per kg and made 20% overall profit.
 at what price per kg did he purchase the lot of another 30 kg rice??
:
Let x = price of the other rice
Find the cost of the first rice
30 * 17.50 = $525
then
total cost = 30x + 525
:
Find the revenue from selling 60 kg for 18.6
60 * 18.6 = $1116, given as 20% above cost
therefore
1.2(30x + 525) = 1116
36x + 630 = 1116
36x = 1116 - 630
x = 486/36
x = $13.50 is cost per kg for the other rice
:
Check this, find the cost for each
525 + 30(13.5) = $930
A 20% increase: 1.2 * 930 = 1116
:
;
3.The ratio of the number of boys and girls in a school is 3:2.
 If 20% of the boys and 25% of the girls are scholarship holders,
 what percentage of the students does not get the scholarship?
:
Let x = the multiplier
then
3x = no. of boys
2x = no. of girls
therefore
5x = total students
then
.20(3x) = .6x boys have scholarships
and
.25(2x) = .5x girls have scholarships
:
5x - .6x - .5x =  3.9x students did not have scholarships
:
Find the per cent that do not have scholarships
{{{(3.9x)/(5x)}}} * 100 = 78%