Housework = 50% = 5 h

Remaining time = 100% – 50% = 50% = 5 h

Baking cake = 20% of Remaining time = 20/100 x 5 h = 1 h#

Assume Mrs Pang had 10u hour at home.

She spent 50% = 5u hour doing housework.

Time remaining -> 10u – 5u = 5u

20% of 5u was spent baking -> 20% x 5u = 1u

We were told she spent 5 hour doing housework.

5u = 5 hour

1u = 1 hour

She spent 1 hour baking.