Question

A fish tank 60 litres of water round to 1 significant figure

40 litres of water rounded to 1 significant figure is removed from the tank
work out the upper bound of the water left in the tank

Answer 1

The upper bound of the water left in the tank, rounded to 1 significant figure, is 6 liters.

Step-by-step explanation:

When rounding to one significant figure, we look at the first non-zero digit. If the digit after it is greater than or equal to 5, we round up, and if it is less than 5, we round down. In this case, the starting volume of water in the tank is 60 liters, which has 2 significant figures. When rounding to 1 significant figure, we round the volume to the first digit after the decimal point, which is 6. Since the next digit, 0, is less than 5, we round down. Therefore, the upper bound of the water left in the tank is 6 liters.