ratio and proportion Model Questions & Answers, Practice Test for ssc cgl tier 1 2024

Answer: (c)

Required compound ratio = ${2/3} × {9/4} × {5/6} × {8/{10}} = 1/1 = 1 : 1$

Answer: (d)

Fineness = ${6 × 15 + 5 × 14 + 4 × {{25}/2}}/{6 + 5 + 4}$

= ${210}/{15}$ = 14 carats

Answer: (a)

Let the number of boys = x

The number of girls = y

According to the question,

x – y = ${(x + y) × 12}/{100}$

⇒25x – 25y = 3x + 3y

⇒22x = 28y⇒x : y = 14 : 11

Answer: (d)

Suppose x number is added to each term, they become in proportion i.e., (4 + x), (10 + x), (12 + x) and (24 + x) are in proportion.

∴ (4 + x) : (10 + x) :: (12 + x) : (24 + x)

⇒${4 + x}/{10 + x} = {12 + x}/{24 + x}$

⇒(4 + x)(24 + x) = (10 + x)(12 + x)

⇒96 + 28x + $x^2 = 120 + 22x + x^2$

⇒28x – 22x = 120 – 96⇒6x = 24

∴ x = 4

Answer: (b)

90% and 97% mixed to form 94% means that the mixing ratio is 3 : 4. The first solution would be

3 × 21/7 = 9 litres.