Question
In a mixture, nitrogen and HCL are present in a 4:1
ratio. After removing 25% of the mixture and replacing it with 'x' liters of HCL, the ratio of nitrogen to HCL in the mixture becomes 1:4. Then, 'y' liters of nitrogen are added to the mixture, resulting in a nitrogen-to-HCL ratio of 3:2. What percentage of 'y' is 'x'?Solution
Let the quantity of the nitrogen initially = β4aβ litres And, the quantity of the HCL initially = βaβ litres Quantity of the nitrogen that is taken out = 4a Γ 25% = a litres Quantity of the HCL that is taken out = a Γ 25% = 0.25a litres According to the question, (4a β a):(a β 0.25a + X) = 1:4 12a = 0.75a + X X = 11.25aβ¦β¦β¦β¦β¦β¦β¦β¦.(1) Again, (4a β a + Y):(a β 0.25a + X) = 3:2 (3a + Y):(0.75a + 11.25a) = 3:2 (From equation 1) 2(3a + Y) = 3 Γ 12 3a + Y = 18a Y = 15x Required percentage = (11.25a/15a) Γ 100 = 75%
2(3/4) of 2880 + 54% of 7520 - ? = 302
Find the value of the following expression:
372 ÷ 56 × 7 – 5 + 2
- What will come in place of (?), in the given expression.
(5Β³ + 3Β²) Γ 2 = ? (1225/25) - (192/96) + (50/5) = ?

What will come in the place of question mark (?) in the given expression?
(555 + 385 - 535) Γ· 15 X ? = 36 X 30
- What will come in place of (?), in the given expression.
75% of 640 β 20% of 150 = ? `(21 xx 51 + 54)/(9 xx 14 - 30 )` =?
95% of 830 - ? % of 2770 = 650