ISRO Scientist or Engineer Refrigeration & Air-Conditioning 2018

Mohan is five times older than his son. After 4 years the sum of their ages will be 44 years. Find the present age of Mohan?

For a sphere of radius 10 cm, the numerical value of surface area is what percent of numerical value of its volume?

A man bought a house and a cart. If he sells the house at 10% loss and cart at 20% gain, he will not lose anything. But, if he sells the house at 5% loss and cart at 5% gain he would lose Rs.100. The amount paid by him for the house and cart will be?

Average marks of 15 students in a class is 145, maximum marks being 150. If two lowest scores are removed, the average increases by 5. Also two lowest scores are consecutive
multiples of 9. What is the lowest score in the class?

In a mixture of wheat and barley, wheat is 60% of 400 kg of mixture. Further, some quantity of barley is added and percentage of wheat becomes 53 $$\frac{1}{3}$$ % .How many kg of barley is added?

I see an object 3 kms to east and 4 kms to north. It appears to be moving at 1 km per minute in south west direction. At what speed (km per minute) is it getting closer to me?

Eigen values of a $$4 \times 4$$ matrix [A] are given as 2, -3, 13 and 7. Then, what is the value of
$$\mid det[A] \mid$$?

The mean value of a function f(x) from point ‘a’ to point ‘b’ is given by

The area of a circle of radius ‘a’ can be found by following integral

In a box there are 5 red balls, 3 blue balls and 2 green balls. If a ball is selected at random what is the probability that it is blue or green?