Mathematics Mcqs

The average of 11 numbers is 10.9. If the average of first six is 10.5 and that of the last six is 11.4 the sixth number is_____________?

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The average of 11 numbers is 10.9. If the average of first six is 10.5 and that of the last six is 11.4 the sixth number is_____________?A. 11.0
B. 11.3
C. 11.4
D. 11.5

Sum of 11 numbers = 11×10.9 = 119.9
Sum of 1st 6 numbers = 6×10.5 = 63
So, sum of last 5 numbers = 119.9-63 = 56.9
And sum of last 6 numbers = 6×11.4 = 68.4
Hence sixth number will be = 68.4-56.9= 11.5

 

What are Prime Numbers?

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What are Prime Numbers?A. Which can be divided by Odd Numbers
B. Which can be divided by Even Numbers
C. Which can be divided by Number 1 & by itself Number
D. Which can be divided by any Number

 

Two automobiles are 150 kilometers apart and traveling toward each other. One automobile is moving at 60km/h and the other is moving at 40km/h mph. In how many hours will they meet?

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Two automobiles are 150 kilometers apart and traveling toward each other. One automobile is moving at 60km/h and the other is moving at 40km/h mph. In how many hours will they meet?

A. 2.5
B. 2.0
C. 1.75
D. 1.5
E. 1.25

One moves at 60km/h, so in an hour, he’ll travel 60km
The other moves at 40km/h, so in an hour, he’ll travel 40km
This is towards each other, so, in an hour, we can say that they’ll get 60+40=100km closer.
This means that they get closer at 100km/h
Given that we have the distance of 150km, and the speed of closure at 100kmh, we can now use the equation
S=D/T
Rearrange to find T (times both sides by T)
S x T = D (now divide both sides by S)
T=D/S
Time = 150km divided by 100km/h
Time = 1.5 hours
Or one hour and 30 minutes