If the average marks of three batches of 55, 60 and 45 students respectively is 50, 55, 60, what is the average marks of all the students?

Weighted average will be more close to the average of that batch which has maximum number of students so aanswer is 54.68

If you want to calculate it by formula then solution is

(55*50 + 60*55 + 45*60)/(55 + 60 + 45) = 54.68.

The average weight of 16 boys in a class is 50.25 kg and that of the remaining 8 boys is 45.15 kg.Find the average weights of all the boys in the class.

In this question weighted average is calculated rather than simple average

(50.25*16 + 45.15*8)/(16+8) = 48.55.

Price of a mobile phone is Rs. 8,000. A man has enough money to purchase 3 mobiles. How many mobile can he purchase if the price is reduced by Rs. 2000?

Minimum amount of money that he has = 8,000 * 3 = 24,000

If price is reduced to 6,000, he can purchase 24,000/6,000 = 4.

In the first 10 overs of a cricket game the run rate was only 3.2 What should be the run rate in the remaining 40 overs to reach the target of 282?

3.2 * 10 = 32

After 10 overs score is 32.

Remaining score = 282 - 32 = 250

Required rate = 250 / 40 = 6.25 runs/over.

A cigarette case is full of cigars and cigarettes, probability of a cigarette is 8/15. What is the ratio of cigars to cigarettes.

In 15 cigars and cigarettes there are 8 cigarettes So ratio between cigars and cigarettes is 8/7. Which means there are 8 cigarettes and 7 cigars..

At a particular time shadow of a pole 40m long is measured to be 30m. If the length of a plaza is 200m then how long would the shadow be at about the same time?

Shadow of 40m pole = 30m

Shadow of 1m pole = 30/40m

Shadow of 200m plaza = (30/40)*200 = 150m.

At an educational trip of a school ratio of boys to girls students was 4/5. how many students were on the tour?

Data is insufficient for this problem. But we can find the answer from the options. As 4 + 5 = 9, So answer should be multiple of 9 to fullfil the condition of 4/5 ratio..

35 Kg of spinach costs Rs. 28. How many Kg of spinach can be bought for Rs. 16?

Amount of spinach which can be bought in Rs. 28 = 35 kg

Amount of spinach which can be bought in Rs. 1 = 35/28 = 5/4 Kg

Amount of spinach which can be bought in Rs. 16 =(5/4)*16 = 20 Kg.

Mental arithmetic is an awesome brain-storming math IQ test that is done without a calculator. It is to check the sharpness of mind and how quickly a student or even an interviewing candidate can solve the arithmetic problems. Most candidates and students opt for mental math classes to practice solving Math problems in the mind and not using the pen or paper. The mental arithmetic involves four types of calculations generally like addition, subtraction, division, and multiplication. Its main aim is to improve cognitive ability and help brain function faster.

This maths IQ test helps you to simplify the calculations and get the answers quickly. Like, if we have to add two numbers like 91 and 45 then use the simplified steps. Firstly, add the second numbers of both the digits like 1 + 5= 6 and then add the first numbers of these digits like 9+4 = 13 so the total answer is 136 where you need to place answers of second numbers on the second place and the answer of first numbers on the first place. This way you can solve the subtraction problems too.

While, in multiplication problems, you have to place zero at the end of two-digit numbers like 3X75, so it goes like 3x70 and 3x5 so the answer is 210+15= 225. This way you will get the exact answers. There are varied rules for square roots, divisions, etc. Here you can learn by practicing the various significant rules of the Mental arithmetic. It will help you to solve tedious questions too.