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Question Number 43196 by rahul 19 last updated on 08/Sep/18
Commented by rahul 19 last updated on 08/Sep/18
Commented by rahul 19 last updated on 08/Sep/18
$$\mathrm{someone}\:\mathrm{pls}\:\mathrm{explain}\:\mathrm{this}\:\mathrm{solution}. \\ $$$$\mathrm{How}\:\left(\mathrm{7}.\mathrm{8}\right)×\mathrm{2}? \\ $$$$\mathrm{Any}\:\mathrm{other}\:\mathrm{way}\:\mathrm{is}\:\mathrm{welcome}. \\ $$
Commented by MrW3 last updated on 08/Sep/18
$${in}\:{each}\:{row}\:{there}\:{are}\:\mathrm{8}\:{small}\:{squares}, \\ $$$${there}\:{are}\:\mathrm{7}\:{ways}\:{to}\:{choose}\:\mathrm{2}\:{consecutive} \\ $$$${ones}.\:{in}\:\mathrm{8}\:{rows}\:{we}\:{have}\:{totally}\:\mathrm{8}×\mathrm{7}\:{ways}. \\ $$$${we}\:{can}\:{do}\:{the}\:{same}\:{in}\:{each}\:{column}, \\ $$$${thus}\:{there}\:{are}\:\mathrm{2}×\mathrm{8}×\mathrm{7}\:{ways}\:{to}\:{choose} \\ $$$$\mathrm{2}\:{consecutive}\:{small}\:{squares}. \\ $$
Commented by rahul 19 last updated on 08/Sep/18
$$\mathrm{thanks}\:\mathrm{sir}. \\ $$