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In an office there are twice as many females as males. 1/4 of the females wear glasses. 3/8 of the males wear glasses. 84 people in the office wear glasses. Work out the number of people in the office.

office that is females with glasses=(2/3) (1/4)=1/6 office that is males wearing glasses=(1/3) (3/8)=1/8 (1/6)/(1/8) = 8/6=4/3 so there is a ratio of 4:3 women to men wearing glasses 84*(4/7)=12 4=48 women w...
WJ
Answered by William J. • Maths tutor
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What is a pathogen?

A microorganism that causes disease
ES
Answered by Emma S. • Biology tutor
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Olly drove 56 km from A to B. He then drives 61 km from B to C. Olly’s average speed from A to B was 70 km/h. Olly took 75 minutes to drive from B to C. Work out Olly’s average speed for his total drive from A to C.

Key fact: Average speed = total distance/ total timeStep 1: find the time taken for Olly to travel from A to B. Using the formula: time taken = distance travelled / speed(56/70 = 0.8 hrs = 48 mins)Step 2: fi...
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Answered by Sacha W. • Maths tutor
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Given the mass number of Aluminium is 27 and the mass number of Oxygen is 16, how many moles of Al2O3 are in 30g? (3 significant figures)

Molar Mass of Al 2 O 3 = 27+27+16+16+16 = 102Mass = mol*Mr so mol = Mass/Mrmol = 30/102 = 0.294117... = 0.294 moles
TG
Answered by Toby G. • Chemistry tutor
3805 Views

Given I climb two steps every second and I have a mass of 50kg, what is the power output of my legs in kilowatts? (3 significant figures)

(There is a diagram showing stairs with steps that are 20cm high) Power = Energy/TimeEnergy required to climb one step = Work Done = Force DistanceForce = Weight = m g = 50 9.81 = 490.5NEnergy = 490.5 0.2 = ...
TG
Answered by Toby G. • Physics tutor
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