7.13 because you would need to add the decimals together
Solving for the angles, we need to apply and use Law of Cosines:
Solving for ∠AB, we have
cos ∠AB = (BC² + CA² - AB²) / 2*BC*CA
cos∠AB = (9²+17² -13²) / 2*17*9
∠AB = 48.94°
Solving for ∠BC, we have
cos ∠BC = (AB² + CA² - BC²) / 2*AB*CA
cos∠AB = (13²+17² -9²) / 2*17*13
∠BC = 31.47°
Solving for angle CA, we have:
∠CA = 180° - 31.47° - 48.94°
∠CA = 99.49°
The smallest angle is 31.47°.
A) 186 minutes
b) 3 tyres
We can take 124 and divide it by 4 to see how long it takes him to fit 1 tyre, then use that number to sort the rest out.
124/4 = 31
It takes Liam 31 minutes to fit one tyre to a lorry.
To fit 6 tyres, it takes 6 x 31 = 186 minutes
If he works for 93 minutes,
93/31 = 3 tyres
Please let me know if you have any questions.