dimensional formula is written using SI units...raised to powers for eg-the unit for velocity is metre per second square metre-length second-time M0L1T-2 L1-length raised to1 M0-mass raised to zero T-2-time raised to -2

if "X" is a price of a orange and one can bye "Y" so, X*Y=40 .........................(1) after reducing price price of one orange is become "0.8X" and one can buy "Y+20" oranges in 40 rypees. so (0.8X)*(Y+20)=40............................(2) from (1)........X=40/Y and from(2)........X=40/(0.8)*(Y+20) than you will get X=0.5 so , 0.8X=0.4 so reduced price of orange is 0.4 rupees.

RS.70.95/- Wholeseller sold at 10% profit therefore selling price of the article is 275. so he pays 12% as sales tax which is 33. Retailer buys at 275 and sells at 15% profit where the selling price would be 316.25. 12% sales tax of it is 33.95 Whole seller and retailer together pays 70.95 as tax.

sorry bro i m cs student.