A single card is drawn from a deck Find the probability of selecting a 10 or a diamond?

for the diamonds - you have a 1in4 chance (25%) 52 cards in the deck, 13 are diamonds or 13:52=1:4 for the 10s - you have 1in13 chance (7.7%) 52 cards in the deck, 4 are 10s or 4:52=1:13