The price of sugar is increased by 20%. By what percent must the consumption of sugar be decreased so that the expenditure on sugar may remain the same ?

A number, whose 4% is 6, is :

1. 24

2. 0.24

3. 150

4. 75

18 hours as a percentage of 3 days is :

1. $\dfrac{18}{3}\times 100\%$

2. $\dfrac{3}{18}\times 100\%$

3. $\dfrac{18}{3\times24}\times 100\%$

4. $\dfrac{3\times24}{18}\times 100\%$

An alloy contains 30% of copper, 30% of zinc and rest nickel. The amount of nickel in 400 gm of alloy is :

1. 40% of 400 gm

2. 30% of 400 gm

3. 70% of 400 gm

4. 400 gm - 30% of 400 gm