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A particle P is projected vertically upwards from a point 20m above the ground with velocity 18m/s, no external forces act on it other than gravity. What will its speed be right before it hits the ground? Give your answer to one decimal place.

To start off we should list what we have and what we want to find. The initial velocity u= 18 m/s (taking upwards to be the positive direction). Acceleration a= - 9.8 m/s² (negative since gravi...

Answered by Jenny N. • Maths tutor

4667 Views

A t-shirt is in two shops, both of which has it on sale. In shop A, the t-shirt originally cost £15, but has been reduced by 30%. In shop B, it used to cost £17 and has been reduced by 40%. In which shop is the t-shirt now cheaper, and by how much?

Shop A:30%=0.31-0.3=0.715x0.7=10.5 --> now £10.50 in Shop A
Shop B40%=0.41-0.4=0.617x0.6=10.2 --> now £10.20 in Shop B
£10.50-£10.20=£0.30=30p
The t-shirt is now cheaper in Shop B by ...

Answered by Freya R. • Maths tutor

3290 Views

Katie wants to know how fast she is riding her bike. She travels 10km in 60 minutes, what is her speed to the nearest decimal place (in m/s)?

60 x 60 = 1200 (to work out the time in seconds)10 x 1000 = 10000 (to work out the distance in metres)
speed=distance divided by time10000 divided by 1200 = 8.3333...
Therefore, Katie is going a...

Answered by Zadie L. • Maths tutor

1402 Views

There are 10 boys and 20 girls in a class. The class has a test. The mean mark for all the class is 60. The mean mark for the girls is 54. Work out the mean mark for the boys.

Mean = Sum of all the numbers/How many numbers there are60=sum of all numbers/30 therefore 1800= sum of all the test scores of class54= sum of all the girls' scores/20 therefore 1080 = sum of all the girl...

Answered by Chimdi O. • Maths tutor

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There are 10 beads in a bag. Four beads are green, six are black. If three beads are taken at random without replacement, what is the probability that they are the same colour?

There are two possible outcomes in which all beads are the same colour: they may be all green, or all black. We need to work out the probability of each outcome to start with. This is done by multiplying ...

Answered by Tom W. • Maths tutor

4532 Views