Which of the two numbers should be reduced in the ratio of 15:19 so that the ratio becomes 3: 4?

Manu works 3 times as fast as Raju. If Raju can complete a job alone in 60 days, then in how many days can they together finish the job?

In an office, 70% of the total number of employees are females. 80 % of the total number of employees, including 85 males, got promotion. If there are 105 female employees, then what percentage of female employees got promotion?

The ratio of the number of boys and girls in a college is 6 : 7. If the percentage increase in the number of boys and girls be 20% and 10% respectively, what will be the new ratio?

The length of a hollow thick cylindrical metallic pipe is 6 cm and its total surface area including the surface at the ends is 98π sq. cm. If the outer diameter is 8 cm, then the inner diameter in cm is 

A man has eaten 100 grapes in 5 days. He eats 6 more grapes every day in comparison to the previous day. How many grapes did he eat on the first day?

If A : B = 1 : 2 , B : C = 3 : 4 , C : D = 6 : 9 and D : E = 12:16 then A : B : C : D : E is equals to -

Milkman has a container filled with a mixture of milk and water which are in the ratio of 7 : 3. How many parts of the mixture needs to be removed and replaced from the water to obtain milk and water in ratio of 1 : 1?