pension contr jack

the only pension contr jack has made prevoiusly is 500 per month which he saves into a personal pension scheme. jack has continued to make these contributons throughout 24-25. although jack has been saving for prevoius 15 yrs he is concerned that he is not saving enough for his retiremtn. jack wants to make max possible amt of additional pension contbut for tax yr 24-25 but only to the extent that the cont will attract tax rleif at higher rate of income tax. his trading profit for 24-25 is 100000.

qtn:
advice jack addtional gross cont he can make at higher rate nd explain y it is tax efficient apporach

i did read the solution in kit but i am having a problem with how to do these kind of qtns. can u plz explain how to do such qtns?