Test: Ratio & Proportion - 2 - UCAT MCQ

Number of children 
49 = k/20
K = 49 × 20
⇒ N = 49 × 20 /3.5
= 280.

Present ratio = 9 : 5. ∴actual values are 9x and 5x.
Hence 9x + 9 : 5x – 5 = 3 : 1 ⇒ x = 4.
∴ numbers are 9(4) = 36 and 5(4) = 20.

Ratio of the amounts collected from 1^st and 2^nd class = (6 × 1): (4 × 30) = 1 : 20.
∴ Amount collected from 1st class passengers = 1/21 x 2100 = 100

Amount of acid in the 1st solution = 0.25 × 200 = 50 g.
Amount of acid in the 2nd solution = 0.4 × 300 = 120 g.
Total amount of acid = 50 + 120 = 170 g.
∴ Required concentration = 170 / (200 + 300) × 100 = 34%

3A = 2B = 4C. Also A + B + C = 390.

⇒ (4 + 6 + 3)A = 390 × 4
⇒ A = 120,
∴ B = 180 and C = 90

C α W²
⇒ C = kW². 4800
= k(20)²
⇒ k = 12.
Now C = 12(8)²
⇒ C =768.

Diagonal of a square = √2 side.
Hence this is the required ratio. So the required ratio is √2: 1.

Present ratio = 4 : 5.
Increase of 10% and 20%.
∴New ratio of salaries will be 4 × 1.1 :5 × 1.2
= 11 : 15.

Amount of gold in 1^st alloy = 0.6 × 12 = 7.2 kg.
Amount of gold in 2^nd alloy = 0.35 × 8 =2.8 kg.
∴ required % age of gold = (7.2 + 2.8) / (12 + 8) × 100
= (10 / 20) × 100
= 50 %.

Value of rupee coins = 10 i.e. 10 coins.
Value of 50 p coins = 4 i.e. 8 coins.
Value of 25 p coins = Rs. 3 i.e. 12 coins.
∴ Ratio of coins = 10 : 8 : 12 ⇒ 5 : 4 : 6.
∴ Number of rupee coins = 5/15 × 300 = 100.
Number of 50 P coins = 4/15 × 300
= 80 and N
Number of 25 P coins = 6/15 × 300
= 120