Quantitative Aptitude - Arithmetic Ability Questions

A boat is moving away from an observation tower. It makes an angle of depression of 60° with an observer's eye when at a distance of 50m from the tower. After 8 sec., the angle of depression becomes 30°. By assuming that it is running in still water, the approximate speed of the boat is

A right circular conical structure stands on a circular base of 21m diameter and is 14m in height. The total cost of colour washing for its curved surface at Rs. 6 per sq. m. is
(Take Π = 22/7 )

A, B and C can complete a work in 20, 24 and 30 days respectively. All three of them starts together but after 4 days A leaves the job and B left the job 6days before the work was completed. C completed the remaining work alone. In how many days was the total work completed?

A man misses a train by 1 hour if he travels at a speed of 4 kmph. If he had increased his speed to 5 kmph, he would gave still missed the train by 24 minutes. At what speed should he have travelled so that he reached the station exactly on time?

ΔABC is right angled at B. BD is an altitude. AD = 3 cm and DC = 9 cm. What is the value of AB (in cm)?

In the following question, four number pairs are given. The number on left side of (–) is related to the number on the right side of (–) with some Logic/Rule/Relation. Three are similar on basis of same Logic/Rule/Relation. Select the odd one out from the given options.

The angle of elevation of the top of a tower from a point A on the ground is 30°. On moving a distance of 20 metres towards the foot of the tower to a point B, the angle of elevation increases to 60°. The height of the tower in meters is

The HCF of 20, 28 and 48 is