Ratio And Proportion(Quantitative Aptitude ) Questions and answers for exam Preparation

Quantitative Aptitude

RATIO AND PROPORTION MCQs

Ratio & Proportion, Ratio, Proportion

Total Questions : 895 | Page 86 of 90 pages

Question 851. Two numbers are in the ratio 5:4 and their difference is 10.What is the largest number?

Discuss Question

Answer: Option B. -> 50
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 852. 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.

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Answer: Option D. -> 240
LET 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

Question 853. Three quantities X, Y and Z are such that XY=kZ where k is constant. Initially, X was at 4 and X:Y:Z was 2:3:4. If the value of Y is changed to 12 and Z is kept constant, find the value of X.

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Answer: Option A. -> 2
X:Y:Z=2:3:4
X=4
THEN, Y=6, Z=8 XY=KZ 4*6=K*8 8K=24 K=3
Y=12, Z=8
X*12=3*8
X=2

Question 854. If X:Y = 2:3, Y:Z = 4:5. Find X:Y:Z.

2:3:5
8:12:15
2:8:5
2:7:5

Discuss Question

Answer: Option B. -> 8:12:15
IF 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)
= 8:12:15

Question 855. Find the mean proportion between 5 and 45.

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Answer: Option B. -> 15
5:X::X:45 X²=45*5 = 225 X=15

Question 856. The plan 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.

1200 m²
1500 m²
12000 m²
15000 m²

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Answer: Option D. -> 15000 m²
ACTUAL LENGTH
= 30*500 CM ACTUAL BREADTH
= 20*500 CM ACTUAL AREA
= 30*20*500*500 = 15000 M²

Question 857. The ratio of two numbers a and b is 3:5. If 2 is added to both the numbers, the ratio becomes 2:3. Find b.

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Answer: Option B. -> 10
A: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

Question 858. The length and breadth of a rectangle are in the ratio 5:4. Find its perimeter if its area is 180 cm²

54 cm
27 cm
12 cm
15 cm

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Answer: Option A. -> 54 cm
LET 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*27
= 54 CM

Question 859. M:N = 3:4, N:O = 5:7 and O:P = 7:9. Then M:P =________?

1/3
7/9
5/12
None of these

Discuss Question

Answer: Option C. -> 5/12
M/P = M/N * N/O * O/P = ¾ * 5/7 * 7/9 = 5/ 12

Question 860. The 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.

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Answer: Option D. -> 108
LET THE NUMBER OF BOYS AND GIRLS IN THE CLASS BE 11X AND 13X. 4 BOYS AND 8 GIRLS JOIN THE CLASS. STRENGTH OF THE CLASS
= 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=108