Question

Brock is training for a Crossfit competition. He began the training by completing pull-ups and box jumps. Originally, his training plan had him completing pull-ups and box jumps at a ratio of 5:4. After two months of training, he decided to focus on his leg strength and adjusted his ratio to 2:7. If he completed 53 box jumps at the end of his training, how many pull-ups did he complete in the initial stage of training?

Answer 1

Brock completed approximately 38 pull ups in the initial stage of training.

Explanation:

We are given the following information in the question:

Ration of pull ups and box jumps initially =

`\displaystyle(5)/(4)`

Ration of pull ups and box jumps later =

`\displaystyle(2)/(7)`

Number of box jumps completed in the end of training = 53

Total number of exercises done in the end = 2x + 7x = 9x

We use the concept of ratio.

`7x = 53\\\\=x = \displaystyle(53)/(7)\\\\\Rightarrow 2x = (106)/(7)\\\\\Rightarrow \text{Total number of excercise} = (477)/(7)`

Initially,

Total number of exercise = 5y + 4y

`9y = \displaystyle(477)/(7)\\\\\Rightarrow y = (477)/(63)\\\\\Rightarrow \text{Pull ups done initially} = 5y = 5* (477)/(63) = 37.85 \approx 38`

Thus, he completed approximately 38 pull ups in the initial stage of training.