I was asked to use VLOOKUP and SUM functions to calculate the market share of an item

With a single formula, how can I pull the market share of "Product A" in May'15 from sales data given below?

Using VLOOKUP and SUM functions.

Please help.


Sales in units
PRODUCTS Jan-15 Feb-15 Mar-15 Apr-15 May-15 Jun-15 Jul-15 Aug-15 Sep-15 Oct-15 Nov-15 Dec-15
Product A 11 7 240 251 177 279 37 45 165 125 26 149
Product B 226 63 18 119 226 32 213 175 42 131 150 34
Product C 32 196 248 300 15 167 177 120 27 33 269 125
Product D 49 212 17 183 188 28 64 17 143 37 126 283
Product E 128 182 146 12 28 35 176 38 217 227 241 88
Product H 300 293 151 69 165 37 80 87 8 12 42 122
Product I 138 72 188 132 12 257 184 223 93 118 98 179
Product J 110 161 109 253 279 104 41 16 1 57 165 207
Product K 278 239 205 278 147 84 111 201 118 276 188 122
Product L 176 139 209 168 52 68 37 207 45 18 23 184
Product M 60 85 296 220 9 262 182 91 255 22 287 91
Product N 153 110 233 292 125 15 134 36 260 276 126 113
Product O 155 185 82 134 60 284 38 157 126 73 116 19
Product P 262 13 136 8 10 91 115 163 8 34 178 201
Product Q 129 159 204 276 223 76 133 38 80 78 238 121
Product R 25 255 172 53 232 277 183 275 158 20 145 273

Is this coursework? If not, why are you wanting a solution involving the use of ONLY those two functions?

Maybe =H7/SUM(H7:H22). Not sure how Vlookup would come into play.

The dates are a bit weird... they are all 16th month... but setting that aside:

=VLOOKUP("Product A",$C$7:$O$22,MATCH(DATE(2015,5,16),$C$6:$O$6,0),FALSE)/SUM(INDEX($D$7:$O$22,,MATCH(DATE(2015,5,16),$D$6:$O$6,0)))

I wouldn't do it that way, however. BUT.... it is possible...