For this question, take note that we have to change the fractions 2/5 and 3/8 as there are 3 units for remainder but 3/8 fraction indicates that there are 8 units for remainder so we must make 3 and 8 the same, so we have to multiply 2/5 by 8 for both numerator and denominator to get 16/40 and 3/8 by 3 to get 9/24 and so, the first 3 lines shows how many units each type of coupon actually has. There are too many units so i did not draw them but if u really cannot see, try drawing it out on your own.

Then now, the problem is each coupon is not $1, so to get the number of units in terms of $, we multiply the coupon by its value accordingly, so $2 coupon must times 2 and so on. This is so that we are able to get the ratio of the corresponding values of the coupons compared to one another. For the first 3 lines, the ratio is in terms of the number of coupons and for the next 3 lines, the ratio is in terms of the total value of each type of coupon.

Lastly, the $5221 is for the 2nd ratio since it is in terms of $. Then, to get the total number, just multiply the total number of units for the first ratio. Now take note that for the second ratio, i am just multiplying the first ratio by some constants so the units for both ratios are actually the same. Of course if u don't think so, u can manually calculate the value of each coupon, then divide by the value to get the number of coupons then add up all 3, you will still get 960 (: