From the question
Percentage markup = 26%
Selling price(SP) = $350
To find the Markup
The formula below will be used

Since Cost price(CP) is not given
Hence, substitute given values to find CP

Solve for CP
Cross multiply

Expand the bracket

Collect like terms

Divide both sides by 126

Hence the cost price is $277.78
To find Markup the formula below will be used

Hence,

Therefore, the markup is $72.22