Merle's spare change jar has exactly 16 U.S. coins, each of which is a 1-cent coin, a 5-cent coin, a 10-cent coin, a 25-cent coin or a 50-cent coin. If the total value of the coins in the jar is 288 U.S. cents, how many 1-cent coins are in the jar?
(1)The exact numbers of 10-cent, 25-cent, and 50-cent coins among the 16 coins in the jar are, respectively, 6, 5, and 2.
(2)Among the 16 coins in the jar there are twice as many 10-cent coins as 1-cent coins.
Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
EACH statement ALONE is sufficient.
Statements (1) and (2) TOGETHER are NOT sufficient.
正确D 错误A
2可以的理由:列方程21x + 5a + 25b + 50c = 288
5a + 25b + 50c 必定是5的倍数,所以21x的尾数必须是3或8
x= 3,8,13,18...一个一个试,最后x只能是3
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