Question

To test whether seeds need water to germinate, Farah sets up two identical dishes of seeds. She waters only dish 1 and keeps dish 2 dry. Which dish is the control, and why is a control needed?

Plan a fair test to find out whether the colour of a cloth affects how quickly it dries in the sun. Write (a) your hypothesis, (b) the variable you change, the variable you measure and two variables you keep the same, and (c) how you will record your results.

Tanvi wanted to find which of two detergents, X or Y, removes ink stains better. She washed a cotton cloth stained with ink using X in hot water, and a silk cloth stained with ink using Y in cold water. She used a spoonful of X but only a pinch of Y, and did the test only once. Point out three mistakes in her test and say how to correct each.