Quantitative Aptitude - Arithmetic Ability Questions

In ΔDEF measure of angle E is 90°. If cosD = 8/17, and DE = 16cm, then what is the length (in cm) of side DF?

An alloy is made by mixing metal A costing Rs 2000/kg and metal B costing Rs 400/kg in the ratio A:B = 3:1. What is the cost (in Rs) of 8 kilograms of this alloy?

The average marks of 45 students is shown as 65. It includes a wrong entry of 84 marks instead of 48 marks. The correct average is:

Seven years ago, the age of Sahil was equal to the present age of Nihal. Sum of Sahil's age 5 year ago and Nihal's age 6 years later is 58 years. If Ruchi is 4 years elder to Sahil, then what will be Ruchi's age (in years) after 10 years?

The time for a train of length 110 metres running at the speed of 72 km/hr to cross a bridge of length 132 metres is

What is the average of all the one digit and two digit natural numbers?

P and Q are at a distance of 240 km from each other at 9:00 a.m. After 1 hour, P starts moving towards Q at a speed of 25 km/hr. At 11 a.m. Q startsmoving towards P at the speed of 18 km/hr. At what time (in p.m.) will they meet?

How many natural numbers are there between 1000 to 2000, which when divided by 341 leaves remainder 5?