Ratio and proportion questions with answers and explanations. Types of ratio and proportion: golden proportion, proportions in math, basic ratio and proportion. Ratio and proportion mcqs with answers pdf, Ratio and Proportion multiple choice questions PDF and Ratio and proportion mcqs online test.
A class has 90 students. If the ratio of boys and girls is 7:8, find the number of boys in the class ?
A. 23
B. 76
C. 93
D. 427x+8x=90 15x=90 x=6 Number of boys=7x=42
Ratio of boys and girls in a class was 11:13. 8 girls and 4 boys join the class from this academic year and the ratio becomes 4:5. Find the strength of the class ?
A. 108
B. 67
C. 96
D. 34= 11x+13x+4+8
= 24x+12 (11x+4):(13x+8) = 4:5 5*(11x+4)=4*(13x+8) 55x+20=52x+32 3x=12 x=4 24x+12=108Perimeter of a triangle is 81 cm. If the sides are in the ratio 4:3:2, find the length of the largest side ?
A. 27 cm
B. 36 cm
C. 45 cm
D. 40 cmLet the three sides be 4x,3x and 2x. 4x+3x+2x = 81 9x = 81 x = 9 Length of the largest side
= 4x = 36 cmM:N = 3:4, N:O = 5:7 and O:P = 7:9. Then M:P = ?
A. 5/12
B. 1/6
C. 1/3
D. 7/9M/P = M/N * N/O * O/P = ¾ * 5/7 * 7/9 = 5/ 12
Length and breadth of a rectangle are in the ratio 5:4. Find its perimeter if its area is 180 cm² ?
A. 98 cm
B. 12 cm
C. 54 cm
D. 27 cmLet the length and breadth be 5x cm and 4x cm.
5x*4x=180
20x²=180
x²=9,x=3 Length = 15cm Breadth = 12cm Perimeter
= 2(l+b)
= 2*27Plan for a rectangular area is drawn to a scale of 1:500. If the length and breadth in the plan is 30 cm and 20 cm, find the actual area ?
A. 12000 m²
B. 15000 m²
C. 1200 m²
D. 1500 m²= 30*500 cm Actual breadth
= 20*500 cm Actual area
= 30*20*500*500 = 15000 m²Ratio of two numbers a and b is 3:5. If 2 is added to both the numbers, the ratio becomes 2:3. Find bv.
A. 12
B. 7
C. 10
D. 5a:b = 3:5 5a = 3b (a+2):(b+2) = 2:3 3(a+2) = 2(b+2) 3a+6 = 2b+4 3*(3b/5) = 2b-2 9b = 10b-10 b =10
If X:Y = 2:3, Y:Z = 4:5. Find X:Y:Z .
A. 8:12:15
B. 2:7:5
C. 2:3:5
D. 2:8:5If A:B = m1:n1 ; B:C = m2:n2
Then, A:B:C = (m1*m2):(n1*m2):(n1*n2)
Therefore, X:Y:Z = (2*4):(3*4):(3*5)
= 8:12:15Find the mean proportion between 5 and 45 .
A. 25
B. 45
C. 5
D. 155:x::x:45 x²=45*5 = 225 x=15
A bag contains 50 paise, 1 rupee and 2 rupee coins in the ratio 2:5:8. If the total amount is Rs. 352, find the total number of coins in the bag ?
A. 250
B. 240
C. 160
D. 200Let the number of 50p, 1 rupee and 2 rupee coins be 2x,5x and 8x. 0.5*(2x)+5x+2*8x = 352 22x=352 x=16 Total no. of coins
= 2x+5x+8x
= 15x = 240