Challenging P6

Hi Ob,

Please help with this P6 question.

1a) The long staircase at an HDB block has 300 steps. Michael climbed 3 steps at one go while his brother, Terry climbed 4 steps. If the steps both of them stepped on is counted once only, how many steps on the long staircase did they step on?

1b) The long staircase at an HDB block has 300 steps. Michael climbed 3 steps at one go while his brother, Terry climbed 4 steps. How many steps on the long staircase did they step on?

MTIA.