Ratio and Proportion Quiz 1

Solution:
Let the Fourth proportional to 5,16,45 be x
Then, 5:16::45:x
=> 5\times x=16\times 45
=> x= \frac{16*45}{5}=144

Solution:
Let Dhoni’s Age be 5x and Virat’s age be 2x
Ten Years hence their ages will be (5x+10) and (2x+10)
So, \frac{5x+10}{2x+10}=\frac{2}{1}
=> 5x+10=4x+20
So, x =10
=> The ages of dhoni = 5x=5\times 10=50
and Virat’s age= 2x=2\times 10=20

Solution:
Ratio of Time Taken =\frac{1}{7}:\frac{1}{8}:\frac{1}{9}=72:63:56

Solution:
Let the shares of the bush, Obama, trump, and Biden be 3x,5x,7x, and 2x respectively.
Then, 7x-2x=200 . So, We get x=40
Obama’s Share= 5\times x=5\times 40=200

Let the original salaries of Salman and Shahrukh be Rs.2x and Rs.3x respectively. Then,\frac{2x+4000}{3x+4000}=\frac{40}{57} ⇔ 57(2x+4000)=40(3x+4000) [/latex]
6x=68000
=> 3x=34000
So, Shahrukh’s Present Salary is = (3x+4000)=Rs. (34000+4000)= Rs.38,000

Let Kurnal ’s amount be A and Hardik’s amount be B
So,\frac{3}{10}\times A=\frac{12}{7}\times B A=\frac{10\times 12}{3\times 7}*B
A:B=40:7
Therefore, B’s Share(Hardik’s Share)=Rs.(2890)\times (47/7)=19,404.28

Solution:
Quantity of oil in 40 liters of mix. =(40)*\frac{10}{16} liters=25 liters
Quantity of oil in 48 liters of the new mix= (25+8)=33 liters
Quantity of water in the new mixture =(48-33) liters=15 liters
Therefore, the ratio of oil to water in the new mixture =33:15= 11:5

Let the number of 25p,10p and 5p coins be 3x,3x and 1x respectively.
Then, sum of their values =Rs.(\frac{25\times 3x}{100}+\frac{10\times 2x}{100}+\frac{5\times x}{100})=Rs.\frac{100x}{100}
So,x=30 and the number of 5p coins are 5\times x=5\times 30=150 coins

Solution:
Let the prices of iPhone and Ipad are Rs. 7x and Rs. 5x respectively. Then,
7x-5x=8000
2x=8000
x=4000
Therefore, Price of Ipad is =(5\times x)=(5\times 4000)=20000

Solution:
Let C=25w and s=5w
Let 1gm of copper is mixed with xgm of silver to get (1+x) gm of the alloy
(1 gm of copper) +(x gm of silver) =(x+1) gm of alloy
⇔ 25w +5w= (x+1)*15w
⇔ 30=15x+15 ⇔ 15=15x ⇔ x=1
Therefore the ratio of copper and silver are =1:x =1:1